Answer:
An ion.
Explanation:
Atoms can gain or lose electrons and become ions, which are atoms that have a positive or negative charge, because they have unequal numbers of protons and electrons.
Hey! I empathize with you, as I just started the energy unit in physics as well!
Alright, lets list what we know, and which equation(s) we need.
PE = Gravitational Potential Energy

m = mass
g = gravity (9.8 m/s^2)
h = height
Guess what?
We need to find the height!
Lets make this more organized:
Known:
m = 40 kg
PE = 14000
g = 9.8 m/s^2
Unknown:
h = ?
================================
Now, if we take a look at the equation PEg = mgh, you will see that we have everything besides the height! So lets solve for the height by substituting in for the variables we know:
14000 J = 40 kg * (9.8 m/s^2) * h
40 * 9.8 = 392
14000 J = 392 * h
14000/392 = h
35.71 m = h
There we go! If you simply list what you know and don't know, you will find the equation you need to solve the problem.
Have a great day and good luck!
Answer:
Explanation:
Given

Motor reverse its direction when \omega =0



(b)





Calcium has 2 valence electrons
Answer:
They have the same amount of energy
Explanation:
Electrons are said to be the subatomic particles that move around the nucleus of an atom. These electrons are negatively charged particles that are seen to be quite smaller than the nucleus of an atom.
The electron shells of these atoms are usually being filled from the inside out with the low-energy shells closer to the nucleus being filled before they can go into the much higher-energy shells that are a bit out