INPUT ARTICLE: Article: Balancing on one foot, especially while moving parts of your body at the same time, will helps you continually adjust to keep your body weight balanced. Stand with both feet together. Raise one foot a few inches off the ground. Stand like this for a few seconds with your eyes open. Then close your eyes and continue to hold the pose. Repeat on the other side. Do this set about 5 times every day. For this move, your arms will swing around like the hands of a clock while you balance on one leg. Stand on one leg and look straight ahead. Put your hands on your hips. Raise one arm up to the 12 o'clock position, then start to move your arm around to the 3, downward to the 6, and over to the 9. Repeat with the other leg and arm. Try to move as little as possible except for your arms. Breathe evenly and concentrate on keeping your body still. Your trunk is the core of your body, and practicing balance with a focus on your trunk will help you stabilize your body and improve your balance. To do trunk turns, stand with your feet just more than shoulder-width apart. Stand on a mini trampoline or other surface that is somewhat squishy or malleable. Hold a heavy item in your hands, such as an exercise ball, a weight, or something similar. Turn your body at your waist to one side and then the other about 10 times. Make the movement a smooth and deliberate motion, but don't swing back and forth. You want your body to work for every twist of your trunk. Don't use the momentum of the twist to propel you into another twist. This exercise requires your legs to be very strong and able to balance while you lift a weight upwards. To do this exercise, balance on your left foot and keep your left knee slightly bent. Bend forward at the hips and touch the ground with your right hand. Hold onto a 5-pound weight with that hand. Raise your right leg behind you. Move smoothly back to an upright position. Repeat with the other leg. Do up to 5 sets of this exercise a few times a week. Practice doing this movement in one clean, smooth motion. Try not to wobble around. Breathe evenly and focus on engaging your core and leg muscles to keep your movement deliberate.

SUMMARY: Balance on one foot. Try the one-legged clock with arms. Do trunk turns. Do a single-leg dead lift.

INPUT ARTICLE: Article: There are many tables that have information on the average bond energies for a specific bond. These tables can be found online or in a chemistry book. It is important to note that these bond energies are always for molecules in a gaseous state. For our example, you need to find the bond energy for an H-H bond, a Br-Br bond, and an H-Br bond. H-H = 436 kJ/mol; Br-Br = 193 kJ/mol; H-Br = 366 kJ/mol. To calculate bond energy for molecules in a liquid state, you need to also look up the enthalpy change of vaporization for the liquid molecule. This is the amount of energy needed to convert the liquid into a gas. This number is added to the total bond energy. For example: If you were given liquid water, you would need to add the enthalpy change of vaporization of water (+41 kJ) to the equation. In some equations, you may have the same bond broken multiple times. For example, if 4 atoms of hydrogen are in the molecule, then the bond energy of hydrogen must be counted 4 times, or multiplied by 4. In our example, there is only 1 bond of each molecule, so the bond energies are simply multiplied by 1. H-H = 436 x 1 = 436 kJ/mol Br-Br = 193 x 1 = 193 kJ/mol Once you have multiplied the bond energies by the number of the individual bonds, you need to then sum all of the bonds on the reactant side. For our example, the sum of the bonds broken is H-H + Br-Br = 436 + 193 = 629 kJ/mol. Just as you did for the bonds broken on the reactant side, you will multiply the number of bonds formed by its respective bond energy. If you have 4 hydrogen bonds formed, you would need to multiply that bond energy by 4. For our example we have 2 H-Br bonds formed, so the bond energy of H-Br (366 kJ/mol) will be multiplied by 2: 366 x 2 = 732 kJ/mol. Again, like you did with the bonds broken, you will add up all of the bonds formed on the product side. Sometimes you will only have 1 product formed and can skip this step. In our example, there is only 1 product formed, so the energy of the bonds formed is simply the energy of the 2 H-Br bonds or 732 kJ/mol. Once you have summed all of the bond energies for both sides, simply subtract the formed bonds from the broken bonds. Remember the equation: H = H(bonds broken) - H(bonds formed). Plug in the calculated values and subtract. For our example: H = H(bonds broken) - H(bonds formed) = 629 kJ/mol - 732 kJ/mol = -103 kJ/mol. The final step to calculating bond energy is to determine whether the reaction releases energy or consumes energy. An endothermic (one that consumes energy) will have a final bond energy that is positive, while an exothermic reaction (one that releases energy) will have a negative bond energy. In our example, the final bond energy is negative, therefore, the reaction is exothermic.

SUMMARY:
Look up the bond energies of the bonds in question. Multiply the bond energies by the number of bonds broken. Add up all of the bond energies of the broken bonds. Multiply the bond energies by the number of bonds formed. Add up all of the formed bond energies. Subtract the formed bonds from the broken bonds. Determine whether the entire reaction was endothermic or exothermic.