1. An average adult’s skin spans 21 square feet, weighs nine pounds, and contains more than 11 miles of blood vessels. The entire skin weighs 9 lbs (pounds).
2. The skin releases as much as three gallons of sweat a day in hot weather. The areas that don’t sweat are the nail bed, the margins of the lips, the tip of the penis, and the eardrums.
3. Body odor comes from a second kind of sweat—a fatty secretion produced by the apocrine sweat glands, found mostly around the armpits, genitals, and anus.
4. Globally, dead skin accounts for about a billion tons of dust in the atmosphere. Your skin sheds 50,000 cells every minute.
5. In blind people, the brain’s visual cortex is rewired to respond to stimuli received through touch and hearing, so they literally “see” the world by touch and sound.
6. Our skin is blessed with the ability to renew itself. The entire skin is renewed in 28 days.
7. Per square inch of human skin contains 50 million bacteria. On oily surfaces like face, the number can ramp up to 500 million.
8. One out of every hundred adult males suffer with acne compared to one out of every 20 in case of adult women. Four out of every five teenagers suffer from some form of acne.
9. Every inch of skin has its own stretchiness and strength designed especially for its position. So, the skin that you see on your belly is very different in strength and elasticity compared to skin that you see on your knuckles.
10. Staphylococcal bacteria is responsible for producing skin boils. This bacteria enters skin through very tiny cuts and travels all the way down to hail follicles (the second layer of the skin) and results in boils.
11. For healthy skin you need to consume vitamin A, D, C and E. Each of these vitamins play a critical role in keeping your skin healthy and youthful.
12. Lipids are natural fats that make your skin’s outer layer moist and healthy. Using harsh cosmetics with detergents and alcohol will deplete your natural lipids and dry your skin out. This is why it is important to use natural products without harsh ingredients.
1. Drink a glass after every bathroom break. Start a habit by linking water with some of your most common daily activities.
Getting up from your desk for a bathroom break? Stop by the kitchen to chug a glass of water after leaving the restroom. Every time you pass the water cooler, fill up a cup.
2. Drinking a full cup before each meal can curb calorie intake because it causes you to feel full.
3. Dilute sugary drinks with water and ice.
If drinking juice, lemonade, or iced tea is a daily habit, water down your sips with H20 and a healthy helping of ice (aim for a one-to-one ratio). You’ll still get the sweetness you’re craving with a healthy dose of the water your body needs.
4. Eat water-rich foods. One sneaky way to increase the amount of water you consume on a daily basis:
eat your H2O. Add fruits and vegetables with high water content to your grocery shopping list.
5. Buy a bottle of water and carry it with you.
One of the main reasons that many of us don’t drink enough fluids is because we don’t have water with us. Keeping a bottle to hand to help keep you hydrated. Once your plastic water bottle is empty refill it and keep it in the fridge.
6. Drink water on your nights out.
A really great tip to drink more water is to substitute every other alcoholic drink on a night out with a glass of water. This is much healthier for your body and will save you from feeling horrible the next morning.
7. Drink through a straw and keep sipping throughout the day. Buy a crazy straw to make sure you do this or buy a water bottle with a sip filter.
8. Try different types of water like, spring, mineral, sparking and flavored water.
You can jazz up water with one of these variations. Remember, whatever helps to make water more enjoyable for you is a good thing.
9.Keep a bottle of water with you in the car and take a sip while you are stuck in traffic.
Driving dehydrates us especially in the hot weather and with the air con that dries out the air. On long car journeys make sure you set reminders on your phone as alerts to have a good drink of water every 30 minutes. In warm weather increase this to 15 minutes.
10.Add deadlines to your water drinking.
Aim to drink a certain amount by 10am, midday, 2pm and in the evening to make sure you hit your target, like this from Life hacker. Use a DIY water bottle with deadlines on so you know when and how to reach your targets during the day. In the evening, you can substitute cold water with a warm water drink to reach your goals.
1. The average adult heart beats 72 times a minute; 100,000 times a day; 3,600,000 times a year; and 2.5 billion times during a lifetime.
2. The volume of blood pumped by the heart can vary over a wide range, from five to 30 liters per minute.
3. The fetal heart rate is approximately twice as fast as an adult’s, at about 150 beats per minute. By the time a fetus is 12 weeks old, its heart pumps an amazing 60 pints of blood a day.
4. The heart does the most physical work of any muscle during a lifetime. The power output of the heart ranges from 1-5 watts. While the quadriceps can produce 100 watts for a few minutes, an output of one watt for 80 years is equal to 2.5 gigajoule.
5. Five percent of blood supplies the heart, 15-20% goes to the brain and central nervous system, and 22% goes to the kidneys.
6. The heart pumps oxygenated blood through the aorta (the largest artery) at about 1 mile (1.6 km) per hour. By the time blood reaches the capillaries, it is moving at around 43 inches (109 cm) per hour.
7. The term “heartfelt” originated from Aristotle’s philosophy that the heart collected sensory input from the peripheral organs through the blood vessels. It was from those perceptions that thought and emotions arose.
8. A woman’s heart typically beats faster than a man’s. The heart of an average man beats approximately 70 times a minute, whereas the average woman has a heart rate of 78 beats per minute.
9. Some heavy snorers may have a condition called obtrusive sleep apnea (OSA), which can negatively affect the heart.
10. Blood is actually a tissue. When the body is at rest, it takes only six seconds for the blood to go from the heart to the lungs and back, only eight seconds for it to go the brain and back, and only 16 seconds for it to reach the toes and travel all the way back to the heart.
11. The right atrium holds about 3.5 tablespoons of blood. The right ventricle holds slightly more than a quarter cup of blood. The left atrium holds the same amount of blood as the right, but its walls are three times thicker.
12. A newborn baby has about one cup of blood in circulation. An adult human has about four to five quarts which the heart pumps to all the tissues and to and from the lungs in about one minute while beating 75 times.
13. During an average lifetime, the heart will pump nearly 1.5 million barrels of blood—enough to fill 200 train tank cars.
14. Laughing is good for your heart. It reduces stress and gives a boost to your immune system
15. The youngest person to receive heart surgery was only a minute old. She had a heart defect that many babies don’t survive. Her surgery was successful, but she’ll eventually need heart transplant.
1. Hard-boiled eggs are rich in protein, and they make a great grab-and-go snack. Just pack a spoon with you—it will help you take the shell off quickly and neatly, especially if the eggs are very fresh.
2. The flesh of kiwis can be super soft, making it hard to separate the peel from this delicious fruit that’s packed with fiber, vitamin C, and folate. Using just a spoon, though, you can peel a kiwi quickly and neatly.
3. Ginger adds a fresh and spicy kick to almost any dish, but it has nooks and crannies that make it difficult to peel and mince. Here’s a quick and easy way to prepare fresh ginger using a spoon or a fork.
4. A fresh baguette features a delicious, crunchy crust and fluffy middle, but when it goes stale, it turns into a rubbery hunk of bread. Bring life back to dried-out, stale bread with this oh-so-easy technique.
5. Cheese is a tasty addition to any party platter, but the softer varieties can be hard to cut. Learn how to cut soft cheese into perfect slices so your guests can enjoy a snack without making a mess.
6. You may have a steel or a sharpener at home, but once a year, get a pro to revive those knives. Your chopping will get faster, more precise—and, believe it or not, safer.
7. Chicken breasts are expensive and can get dull after a while; thighs are juicier, cheaper, and more flavorful.
8. Do your scrambled eggs slide off the pan if you don’t use oil or butter? They should. Might be time for an upgrade.
9. Put the lid on the pot to make your water boil faster. Seems obvious, but if you don’t know, now you know.
10. Avoid evil glass cutting boards. And they’re all evil. Glass cutting boards send shivers down your spine when you use them. They dull your knives. They’re slippery. And they’re hard to use. Use wood, bamboo or plastic instead.
1. Get the whole family moving – Plan times for everyone to get moving together. Take walks, ride bikes, go swimming, garden or just play hide-and-seek outside. Everyone will benefit from the exercise and the time together.1. Get the whole family moving – Plan times for everyone to get moving together. Take walks, ride bikes, go swimming, garden or just play hide-and-seek outside. Everyone will benefit from the exercise and the time together.
2. Keep things positive – Kid’s don’t like to hear what they can’t do, tell them what they can do instead. Keep it fun and positive. Everyone likes to be praised for a job well done. Celebrate successes and help children and teens develop a good self-image.
3. Limit TV, video game and computer time – These habits lead to a sedentary lifestyle and excessive snacking, which increase risks for obesity and cardiovascular disease. Limit screen time to 2 hours per day.
4. Put sweets in their place- Occasional sweets are fine, but don’t turn dessert into the main reason for eating dinner. When dessert is the prize for eating dinner, kids naturally place more value on the cupcake than the broccoli. Try to stay neutral about foods.
5. Kids do as you do. Be a role model and eat healthy yourself. When trying to teach good eating habits, try to set the best example possible. Choose nutritious snacks, eat at the table, and don’t skip meals.
6. Have the fun in the kitchen- Children are more likely to become adventurous eaters if they know how to cook. Make it fun by giving them their own aprons and letting them help you regularly with small tasks in the kitchen. As they get older and more confident, let them cook dinner once a week.
7. Don’t give up- Our research shows that most babies and young children need to try something new seven to ten times before they like it. So don’t be afraid to introduce children to new or more exotic tastes. A good tactic to get kids to eat a wide variety of foods is to tell them that tasting new things is a sign they’re growing up. Or, take them shopping and let them choose a new, healthy food to serve at home with something they already like.
8. Exercise is essential as well-Establish exercise habits in your kids as early as possible, say by the age of 5-6. Heavy weight training exercise is not advisable but daily 10-15 minutes of exercises like stretching or brisk walking should be instilled. Exercises like cycling, jumping ropes or swimming should be encouraged in kids.
9. Stay involved – Be an advocate for healthier children. Insist on good food choices at school. Make sure your children’s healthcare providers are monitoring cardiovascular indicators like BMI, blood pressure and cholesterol. Contact public officials on matters of the heart. Make your voice heard.
10. Start them young- Food preferences are developed early in life, so offer variety. Likes and dislikes begin forming even when kids are babies. You may need to serve a new food a few different times for a child to accept it. Don’t force a child to eat, but offer a few bites. With older kids, ask them to try one bite.
1. Studies suggest that people who exercise in the morning are relatively slimmer and healthier than the ones who exercise later in the day. So carry the feel good hormones and energy throughout the day by doing your exercise in the morning.
2. People who all are want to lose their weight, their main meals are well managed, however, snack is an area where most fall for unnecessary food and jeopardise weight loss. It’s a great idea to pack your own snack at work or on the go.
3. Never, Ever Drink Sweetened Soda. But go ahead, have a glass of wine now and then. Low-carb is fine, too, in moderation.
4. Run Intervals: It’s easier to alternate between hard and easy running instead of going for a long run—especially if you don’t like running. Plus, you’ll be done faster and burn more fat.
5. Skipping breakfast won’t help you lose weight. You could miss out on essential nutrients and you may end up snacking more throughout the day because you feel hungry.
6. Fruit and vegetables are low in calories and fat, and high in fibre – 3 essential ingredients for successful weight loss. They also contain plenty of vitamins and minerals.
7. Cut down on alcohol. A standard glass of wine can contain as many calories as a piece of chocolate. Over time, drinking too much can easily contribute to weight gain.
8. Sleep is a cornerstone of weight management because of the impact it has on your hormones that control how you burn fat, how you store fat, and how you’re maintaining muscle. The better your hormone balance, the better your weight management.
9. Also, most of the time, the snacks which are high in salt are most probably fried too, which is a total no-no if you want to lose weight. Veggie sticks or homemade crisps with salt and fat control work the best.
10. Walking when the weather’s nice is a super-easy way to keep fit, says Diane Virginias, a certified nursing assistant from New York. “I enjoy the seasons,” she says, adding that even when she’s short on time she’ll go out for a few minutes. “Even a five minute walk is a five minute walk.”
What is Blood Circulation?What is Blood Circulation?Blood circulation is the constant movement of blood throughout the body, made possible by the pumping of the heart. As blood circulates, it delivers essential nutrients and oxygen to all organs and cells in the body. Blood flows through a series of tubes called blood vessels. Arteries are the vessels that carry blood away from the heart, while veins carry blood back toward the heart. Certain parts of the circulatory system present particular challenges to the body.
Signs of Poor Blood CirculationSpecific signs of poor blood circulation include:
1. Diminished energy and feelings of tiredness.
2. Numbness, tingling, or cold sensations in the hands and/or feet.
3. Leg cramps and/or aches.
4. Visible skin discoloration, swelling, or ulcers in the leg.
5. Recurrent calf pain.
6. Sores, cuts, or scratches that heal unusually slowly.
7. Hypertension and high blood pressure.
8. Loss of appetite.
9. Erectile dysfunction.
How to Improve Blood CirculationIt isn’t always necessary to take prescription drugs to improve health, and improving blood circulation doesn’t have to be difficult. Improving your circulatory system typically requires adding certain foods to your diet and activities to your routine, while eliminating other foods and behaviors. Sometimes, simply cutting back on unhealthy habits and enjoying certain treats in moderation is enough to dramatically improve circulation.
21 Natural Ways to Improve Blood Circulation
• Eating super fruits is the good remedy for improve our blood circulation. Regular consumption of these delicious snacks makes capillary walls stronger and prevents poor circulation. High-fiber goji berries have a high fiber content, which strengthens the immune system and improves overall circulation function. The classic summer treat is high in lycopene, an antioxidant that has been linked to improved blood circulation.
• Far infrared radiation therapy harnesses the sun’s natural healing energy to improve blood circulation, relieve tension, reduce inflammation, strengthen the immune system, and more. The far infrared rays penetrate the body, triggering the release of waste and toxins, which often block the circulatory system from functioning effectively.
• Doctors warn not to wear tight clothing for extended periods of time. Skinny jeans and other extremely tight garments can hinder circulation. Loose or lightly fitted clothing ensures that blood can circulate normally through the body.
• Exercise is a great way to improve circulation. Any activity that gets your blood pumping, from jogging to biking to dancing, will have a major impact. Exercise strengthens the entire cardiovascular system and enables the heart to pump blood through the circulatory system more effectively.
• If you don’t smoke, decide right now that you will never start. If you already smoke, know that it’s essential for your overall health to quit as soon as possible. The benefits of quitting will begin as soon as you stop smoking and will continue over time.
• A good massage can stimulate blood flow in a way that is remarkably similar to exercise. This direction promotes the flow of venous blood and lymph throughout the body and improves overall circulation.
• Leg elevation is a good way to directly improve circulation as well as to promote relaxation.
• Drinking plenty of water ensures that the entire circulatory system continues to work efficiently. Our organs need to stay hydrated to function at their highest levels. Even our blood is, in large part, made up of water.
• Eating a variety of healthy nuts is an excellent way to keep your blood circulating at optimal levels.• While some research has indicated that moderate amounts of coffee may improve cardiovascular health, this finding is not necessarily true for all caffeinated drinks. Caffeine can have a dehydrating effect on our bodies.
• Natural herbs like cayenne and Gingko Biloba can aid in the development of healthy circulation.• Green tea is rich in antioxidants that provide countless health benefits, including improved blood circulation. Specifically, green tea helps to improve the function of endothelial cells.
• Dark chocolate contains cocoa, an ingredient widely known to improve blood flow.
• Eating too much salt can also have a negative impact on blood circulation. High salt intake can harden the arteries, which prevents blood from flowing freely through the body.
• Hydrotherapy, which simply means any treatment involving water, can improve the body’s circulatory system. Warm or hot water relaxes tense muscles and increases oxygen flow through the body.
• Over time, high stress levels can have a severe negative impact on health, including blood circulation. Luckily, much can be done to relieve stress and increase your overall feeling of calm.
• For many of us, moderate alcohol consumption is harmless and can even be healthy.
• Rebounding therapies can have a remarkable impact on blood circulation.
• Dry skin brushing can remove dead skin cells and improve overall circulation.
• Manual lymph drainage therapy unclogs swollen lymph nodes and eliminates waste to improve circulation.
1. TAKE A 20-MINUTE NAP TO RECHARGE YOUR BODY + MIND
Anyone else feel exhausted by 2pm? Well, studies have shown that you don’t have to wait ’til bedtime to reenergize your body. In fact, many sources recommend getting in a 20-minute nap every day. According to The national sleep foundation, “This type of nap provides significant benefit for improved alertness and performance without leaving you feeling groggy or interfering with nighttime sleep.” Um, sign me up!
2.CREATE A LIST OF ACTION ITEMS FOR OCCASIONAL FREE TIME
Ahh a rare moment of free time. But since you’re busy almost every other minute of the day, you have no idea what to do with yourself! Browse Facebook? Check…my email? Nay! Write down a list of easy action items you can do during those brief moments of peace and keep it on your desk, where you’ll always see it. Some simple ideas are to meditate, enjoy a healthy snack, down a bottle of water, or go for a quick walk. So next time you have a ten-minute gap in your schedule, you’ll use it to replenish your mind + body instead of deteriorating it.
3. LAY OUT ATHLETIC CLOTHES AND A MINT EACH NIGHT
Plan on going for a run in the morning or getting to the gym for an early AM workout? Set out your workout clothes and any necessary gear next to your bed each night. It’ll be much easier knowing you don’t have to use your brain to find your socks or shorts as soon as you wake up.
If your workout clothes don’t inspire you to get up and go, place a mint or gum next to your alarm clock. Pop it in your mouth as soon as you wake up. The chewing gum alone will wake the brain up to help us focus at the task ahead (like crawling out of bed). Mint also helps to give the brain a jolt to awaken the senses and help inspire you to get your workout in.
4. GRAB-AND-GO SNACKS
While meal prepping can significantly increase the likelihood you’ll stick to your diet, it requires a bit of planning and effort. In the long run you’ll actually save time, money, and calories by cooking all of your meals in the beginning of the week. But if you’re not ready to commit to a full week’s worth of prep, creating on-the-go snacks and hunger-pang fighting treats can help you from overindulging at lunch and dinnertime. Separate grapes, low-sodium pretzels, and carrot sticks with hummus into zip lock baggies to hide in your desk drawer, fridge, or purse in time of need.
5. DRINK 2 CUPS OF WATER BEFORE EVERY MEAL
Drink up! A 2015 study published in the journal Obesity revealed drinking 2 cups of water 30 minutes before participants ate led to moderate weight loss over the course of 12 weeks. By simply drinking water when you first wake up, go out for lunch, or get home from work, you can improve your health without having to do much. Plus, keeping the body hydrated is essential to remove waste, lubricate joints, aid in digestion, and fight off headaches, dry mouth, and dizziness.
“The beauty of these findings is in the simplicity,” said the study’s co-author Dr. Helen Parretti, a researchers at the University of Birmingham, in a statement. “Just drinking a pint of water three times a day before your main meals may help reduce your weight. It’s something that doesn’t take much work to integrate into our busy everyday lives.”
6.DRINK MORE FLUIDS
I know, you’ve heard this about 900 times, but it’s so true! Since I sit in front of a computer for much of the day, I notice that I occasionally get headaches. Instead of taking pain relievers, I just drink more water! A lack of fluids can be a big cause of fatigue and head pains, but the solution is so simple. Drink up!
7. CREATE A WEEK’S WORTH OF HEALTHY MEALS IN ONE NIGHT
You may not have time to cook every day, but you likely do have a couple hours to prepare a stock of meals that you can have for the upcoming week. This way, you won’t be rushing around or have to resort to fast food. You can cook healthy options like fish and veggies and just keep it in ready-to-go tupperware containers in your fridge. Life changer.
8. RELIEVE STRESS
The stress you deal with every day, at work, at school, on the roads, and at home affects your health and your performances. You overeat, you can’t focus, and you are always irascible. Hypertension and anxiety are only one-step away, and with them, your overall health and well-being are compromised. To reduce stress, take up exercising, even in the form suggested above, meditate, laugh, give in to your hobbies, listen to music, and let it all out in writing!
9. SURROUND YOURSELF WITH LIKE-MINDED OPTIMISTIC PEOPLE WHO LIVE HEALTHY LIFESTYLES!
It is easier to live healthily when everyone in your entourage shares your ideals, trust me. My former friends tried to persuade me to cheat on my diet and give up my exercising routines all the time, and turned their back on me when I refused. I found new friends, with similar habits, and living healthily feels a lot easier with their support.
10. DITCH YOUR BAD HABITS
Do you smoke, indulge in sweets, or exaggerate with alcohol? You should do something about it! I know it’s difficult, but think of how harmful smoking can be, how excessive consumption of sweets can lead to diabetes and obesity, and how alcohol and other abuses can undermine your health and your relationships.
Lead can enter drinking water when service pipes that contain lead corrode, especially where the water has high acidity or low mineral content that corrodes pipes and fixtures. The most common problem is with brass or chrome-plated brass faucets and fixtures with lead solder, from which significant amounts of lead can enter into the water, especially hot water.
Homes built before 1986 are more likely to have lead pipes, fixtures and solder. The Safe Drinking Water Act (SDWA) has reduced the maximum allowable lead content — that is, content that is considered “lead-free” — to be a weighted average of 0.25 percent calculated across the wetted surfaces of pipes, pipe fittings, plumbing fittings, and fixtures and 0.2 percent for solder and flux.
Corrosion is a dissolving or wearing away of metal caused by a chemical reaction between water and your plumbing. A number of factors are involved in the extent to which lead enters the water, including:
• the chemistry of the water (acidity and alkalinity) and the types and amounts of minerals in the water,
• the amount of lead it comes into contact with,
• the temperature of the water,
• the amount of wear in the pipes,
• how long the water stays in pipes,
• and The presence of protective scales or coatings inside the plumbing materials.
Health Effects of Exposures to Lead in Drinking Water:
Is there a safe level of lead in drinking water?The Safe Drinking Water Act requires EPA to determine the level of contaminants in drinking water at which no adverse health effects are likely to occur with an adequate margin of safety. These non-enforceable health goals, based solely on possible health risks, are called maximum contaminant level goals (MCLGs). EPA has set the maximum contaminant level goal for lead in drinking water at zero because lead is a toxic metal that can be harmful to human health even at low exposure levels. Lead is persistent, and it can bio-accumulate in the body over time.
Young children, infants, and fetuses are particularly vulnerable to lead because the physical and behavioral effects of lead occur at lower exposure levels in children than in adults. A dose of lead that would have little effect on an adult can have a significant effect on a child. In children, low levels of exposure have been linked to damage to the central and peripheral nervous system, learning disabilities, shorter stature, impaired hearing, and impaired formation and function of blood cells.The Centers for Disease Control and Prevention (CDC) recommends that public health actions be initiated when the level of lead in a child’s blood is 5 micrograms per deciliter (µg/dL) or more.
It is important to recognize all the ways a child can be exposed to lead. Children are exposed to lead in paint, dust, soil, air, and food, as well as drinking water. If the level of lead in a child’s blood is at or above the CDC action level of 5 micrograms per deciliter, it may be due to lead exposures from a combination of sources. EPA estimates that drinking water can make up 20 percent or more of a person’s total exposure to lead. Infants who consume mostly mixed formula can receive 40 percent to 60 percent of their exposure to lead from drinking water.
Even low levels of lead in the blood of children can result in:
• Behavior and learning problems
• Lower IQ and hyperactivity
• Slowed growth
• Hearing problems
• AnemiaIn rare cases, ingestion of lead can cause seizures, coma and even death.
Lead can accumulate in our bodies over time, where it is stored in bones along with calcium. During pregnancy, lead is released from bones as maternal calcium and is used to help form the bones of the fetus. This is particularly true if a woman does not have enough dietary calcium. Lead can also cross the placental barrier exposing the fetus to lead. This can result in serious effects to the mother and her developing fetus, including:
• Reduced growth of the fetus
• Premature birthAdults:Lead is also harmful to adults.
Adults exposed to lead can suffer from:
• Cardiovascular effects, increased blood pressure and incidence of hypertension
You probably know water’s chemical description is H2O. A water molecule consists of one atom of oxygen bound to two atoms of hydrogen. The hydrogen atoms are “attached” to one side of the oxygen atom, resulting in a water molecule having a positive charge on the side where the hydrogen atoms are and a negative charge on the other side, where the oxygen atom is. Since opposite electrical charges attract, water molecules tend to attract each other, making water kind of “sticky.” The side with the hydrogen atoms (positive charge) attracts the oxygen side (negative charge) of a different water molecule.
All these water molecules attracting each other mean they tend to clump together. This is why water drops are, in fact, drops! If is wasn’t for some of Earth’s forces, such as gravity, a drop of water would be ball shaped — a perfect sphere. Even if it doesn’t form a perfect sphere on Earth, we should be happy water is sticky.
Water is called the “universal solvent” because it dissolves more substances than any other liquid. This means that wherever water goes, either through the ground or through our bodies, it takes along valuable chemicals, minerals, and nutrients.
Pure water has a neutral pH. Pure water has a pH, of about 7, which is neither acidic nor basic.
Physical and Chemical Changes:
A physical change is one in which there is no change in the molecules which make up a given substance. Turning water into ice or vapor does not constitute a chemical change because the same molecules make up the liquid, solid and vapor states of water. The only difference between ice, steam and water is this: molecules in ice essentially have no freedom. The only vibrate within the crystal. The molecules in water are free to move within the limits of the container, as limited by gravity. The molecules in stream are completely free to move within the container, if any. They are essentially unaffected by gravity.
A chemical change occurs when new molecules are formed as a result of the change.
When water turns to steam at 212°F, a physical change occurs. On the other hand, when propane gas is ignited, it turns to carbon dioxide and water vapor in a chemical change. And change, of course, continues all the time. Let’s briefly consider the types of change by examine the compounds and mixtures.
Compounds and Mixtures:
How can one distinguish between compounds and mixtures? A compound has a definite and unvarying composition.
Water is a typical compound. It is composed of two elements hydrogen and oxygen in definite proportions. Regardless of where one ands water, it always consists of these two elements and always in the same proportion. Salt is another common compound. Whether it comes from a salt mine or is produced in a laboratory, salt is a compound of the two elements sodium and chlorine in an unvarying ratio.
Water, as a typical compound, also suggests another characteristic of the compound, namely a unique “personality” of its own. Although made up of hydrogen and oxygen, water is quite different from these two elements both physically and chemically. And so we should add to our definitions: a compound has well defined characteristics of its own, usually entirely different from those of its component elements.
Further, water freezes at 32°F and boils at 212°F. This indicates another characteristic of the compound: a pure compound has a definite freezing and a definite boiling point.
And finally, water, as a typical compound, is a uniform substance no matter whether one is considering a drop, a glassful or a lake of it. Thus, a compound is homogeneous.
In sharp contrast, a mixture will vary in the amount of the ingredients it contains. A mixture of sand and salt, for example, may have a bit of salt and a large amount of sand. Or it may be a blend of a large amount of salt and sand. No exact ratios of substances are necessary to constitute a mixture. At the same the ingredients in a mixture continue to maintain their essential properties. The salt still tastes salty; the sand continues to be gritty. The properties of the mixture are simply the total of the separate properties of the salt and sand. In this salt sand mixture the original ingredients could be recovered through some type of mechanical process. And finally, a mixture may have varying proportions of its ingredients in different parts of the sample. There may be more salt than sand at the bottom and less at the top of a mixture. In a word, mixtures are usually heterogeneous.
To a chemist, the term “pure” has meaning only in the context of a particular application or process. The distilled or de-ionized water we use in the laboratory contains dissolved atmospheric gases and occasionally some silica, but their small amounts and relative inertness make these impurities insignificant for most purposes. When water of the highest obtainable purity is required for certain types of exacting measurements, it is commonly filtered, de-ionized, and triple-vacuum distilled. But even this “chemically pure” water is a mixture of isotopic species: there are two stable isotopes of both hydrogen (H1 and H2, the latter often denoted by D) and oxygen (O16 and O18) which give rise to combinations such as H2O18, HDO16, etc., all of which are readily identifiable in the infrared spectra of water vapor. And to top this off, the two hydrogen atoms in water contain protons whose magnetic moments can be parallel or antiparallel, giving rise to ortho- and para-water, respectively. The two forms are normally present in a o/p ratio of 3:1.
The amount of the rare isotopes of oxygen and hydrogen in water varies enough from place to place that it is now possible to determine the age and source of a particular water sample with some precision. These differences are reflected in the H and O isotopic profiles of organisms. Thus the isotopic analysis of human hair can be a useful tool for crime investigations and anthropology research.
Current views of water structure
The present thinking, influenced greatly by molecular modeling simulations beginning in the 1980s, is that on a very short time scale (less than a picosecond), water is more like a “gel” consisting of a single, huge hydrogen-bonded cluster. On a 10-12-10-9 sec time scale, rotations and other thermal motions cause individual hydrogen bonds to break and re-form in new configurations, inducing ever-changing local discontinuities whose extent and influence depends on the temperature and pressure.