I'm not exactly sure but I'm thinking that it's the last one. Sorry if I'm wrong
I think it because of UV rays ultra violet ray which can make their colors different
Answer:
The force acting on a body is always equal to the product of the mass of the body and its acceleration.
Explanation:
The force of a body is defined as the product of mass and acceleration of the body.
According to Newton's second law, wherever there is a change in momentum of the body for an interval of time, there is a force acting on it.
F = (mv - mu) / t
= m (v -u) /t
= m a
Where,
(v - u)/t - is the change in velocity of the body in the interval of time. It is equal to the acceleration of the body.
Hence, the equation for the force for any body becomes, F = m x a
The answer is group 18.
Explanation:
Group 18 is known as the Noble Gases. They are the most stable elements because they have a full outer shell of valence electrons, so they have no need to bond with other elements.