Please check my answers:
1.When an exothermic phase change occurs, such as freezing water into ice crystals, where does the energy released go?
my answer: into the surroundings and the environment
2.When a flashlight battery runs out of energy (charge) does that mean the energy has been destroyed? Why or why not?
my answer:
energy is neither created nor destroyed, it just changes form, from chemical energy to electrical energy, and then electrical back to chemical, over and over again.
3.Describe what happens on the molecular level when hot water is poured over ice to melt it.
my answer: When hot water molecules collide with ice molecules, they transfer energy to the ice. This causes the ice molecules to vibrate. If they vibrate hard enough, they will break the bonds keeping them in the ice crystal and become liquid water.
4. Explain why wood insulates and metal conducts heat energy.
My answer: the molecules in the wood were bonded together when the tree was alive and producing new wood. The wood molecules are not free to bump into each other with the same energy of collision that the metal atoms in the fork have. The wood molecules are not able to transfer as much energy and so do not get as hot.
1. Your answer is correct. When an exothermic phase change occurs, such as freezing water into ice crystals, the energy released goes into the surroundings and the environment. This energy is typically released in the form of heat.
2. Your answer is partially correct. Energy is indeed neither created nor destroyed, but it can be transformed from one form to another. When a flashlight battery runs out of energy, it means that the chemical energy stored in the battery has been converted into electrical energy to power the flashlight. Once the chemical energy is depleted, the battery can no longer produce electrical energy, but the energy itself has not been destroyed. It has just been converted into another form or dissipated as heat.
3. Your answer is largely correct. When hot water is poured over ice to melt it, the hot water molecules transfer energy to the ice molecules through collisions. This transfer of energy increases the vibration of the ice molecules. If the ice molecules vibrate with enough energy, they can overcome the intermolecular forces holding them together in the solid state, which results in breaking the bonds and transitioning into the liquid state.
4. Your answer is partially correct. Wood acts as an insulator because the molecules in wood are bonded together, providing a barrier for the transfer of heat energy. These bonded wood molecules restrict the movement of heat-carrying particles, such as electrons and phonons, reducing their ability to transfer energy. On the other hand, metals, like in the case of a metal fork, have loosely held or delocalized electrons that can move freely within the metal's structure. This enables metals to efficiently conduct heat energy through the movement of these free electrons, resulting in better heat conduction compared to wood.