What causes a spring to bounce up when it is pushed down and then released?
(a) Pushing the spring down gives it stored mechanical energy that turns into motion (b)The stored chemical energy in the spring turns into motion. (c) The chemical energy in the spring makes it move and bounce up. (d) Pushing the spring downturns chemical energy into mechanical energy.

(a) Pushing the spring down gives it stored mechanical energy that turns into motion

Explanation:

Pushing on the spring causes the mechanical energy, of pushing on the spring, to be stored in the spring through potential elastic energy. Due to the elasticity of the spring, when the spring is released and resumes its initial shape the stored energy is released and can be used to do work such as motion.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.

the answer is 0.42 is that is an option. this question provides no info