We call it a "green" leaf because green light bounces off of it and enters our eyes. Other colors of light are absorbed by the leaf and stop right there.
If there's no green light to bounce off of the leaf, then no light at all comes from it.
When we look at an object that has no light coming from it, we describe the object as "black". We only know it's there because of its background and surroundings.
(Choice - A)
Yes, because the moon rotates at a different rate than what it usually do.
If an object is moving with a constant velocity, then by definition it has zero acceleration. So there is no net force acting on the object. The total work done on the object is thus 0 (that's not to say that there isn't work done by individual forces on the object, but the sum is 0 ).
Yes, if the temperature increases, than that means the particles are moving faster. Temperature is the measure of movement of particles in an object or substance.
By thermal energy, you mean adding heat correct....? I'm not very good at this sort of thing, but I gave you what I have..
Gamma rays<span> are produced in the disintegration of radioactive atomic nuclei and in the decay of certain subatomic particles. ... When an unstable atomic nucleus decays into a more stable nucleus (see radioactivity), the “daughter” nucleus is sometimes produced in an excited state.</span>