Q: Regular exercise is a key to bone health. Bone is living tissue and, like muscle, it weakens if not exercised. High-impact or low-impact weight-bearing exercises are effective ways to exercise. Bones become stronger when called upon to bear weight. High-impact weight-bearing exercises are: dancing, high-impact aerobics, hiking, jogging/running, jumping rope and stair climbing. Low-impact weight-bearing exercises include: the elliptical machine, low-impact aerobics, stair-climbing machines, and walking on a treadmill or outside. Resistance exercises are also effective in improving muscle mass and strengthening bone. An example of a resistance exercise is weight training (free weights or weight machines). Staying physically active has the added benefit of helping with your coordination and keeping your reflexes sharp which will lower your risk of falling. If you're fit, you're less likely to lose your balance. Choose the right shoes to reduce your chances of breaking a bone. Falls are the most common cause of broken bones among the elderly. Wear comfortable shoes with rubber soles. Avoid sneakers with deep treads. Women: refrain from wearing high heels when you can. Select winter boots with rubber soles for added traction. Broken bones are often caused by in-home falls. A shoe or toy might be out of place, a stairway unlit, a room too dark. Your home should be as safe as possible to decrease your chances of having an accident leading to a broken bone. Use nightlights so that you'll be able to move safely through the house. Keep the house free of items which present a hazard. Shoes can be placed against a wall or in a closet rather than in the middle of the floor. Electric wire and telephone cord can be tucked behind furniture or stapled to baseboards. Use a handrail when climbing the stairs. Install a handrail if you don't have one. When entering a room, be aware of steps and thresholds. Carpets and area rugs should be tacked or fixed to the floor to avoid slipping. Place florescent tape at the top and bottom of your stairs. Be sure your stairs are well lit. Make your bathroom safe. Use a rubber mat in the shower or tub. Install a grab rail for the tub or shower. Taller "comfort height" toilets also make it easier for the elderly to get up and down, reducing falls. Use wall switches for lamps if you don't have an overhead light, so that you don't have to cross a room in the dark to get to your lamp. Keep a flashlight beside your bed.
A: Exercise to strengthen your bones. Prevent falls by wearing proper footwear. Create a fall-free environment.

Q: The pH is a measure of the concentration of hydrogen ions in a solution. A solution with a high concentration of hydrogen ions is acidic. A solution with a low amount of hydrogen ions is basic, or also known as alkaline. Hydrogen ions, also known as hydronium, are written shorthand as H+ or H3O+. Know the pH scale. The pH scale is usually presented from 0 to 14. The lower the number, the more acidic the solution. The higher the number, the more basic the solution. For example, orange juice would have a pH of 2 because it is quite acidic. In contrast, bleach has a pH of 12 as it is quite basic. Numbers in the middle of the scale are neutral, such as water, with a pH of 7. One level of pH is a 10x difference. For example, when comparing pH 7 to pH 6, pH 6 is ten times more acidic than pH 7. Furthermore, pH 6 would be 100 times more acidic than pH 8. The pH scale is calculated by a negative logarithm. A negative logarithm of base b is simply how many times a number must be divided by b to reach 1. The pH equation can be seen as follows: pH = -log10[H3O+]. The equation can sometimes be seen as pH = -log10[H+]. Know that whether the equation has H3O+ or H+, they are the same. It is not vital to have a firm understanding of what a negative log is to calculate pH. Most calculators used at high school and post secondary level will have a log button. Concentration is the number of particles of a compound in a solution relative to the volume of the same solution. For pH, you have to use molar concentration for the formula to work out. Molar concentration, which is also called molarity, denotes the number of moles of dissolved compound per liter of solution. Its units are moles per liter (mol/L), also called molar (M). If you're using a solution in a lab, the concentration will be written on the bottle. When working on your chemistry homework, the concentration will usually be given to you.
A:
Know what pH actually is. Define pH in an equation. Understand concentration.