The atomic number of an atom says how many protons it has. This number cant change, since the atomic number is what gives elements their identities (in the periodic table, at least).
The mass number, on the other hand, says how many protons AND neutrons the atom has (so, the sum of P+ and N0). So, electrons have nothing to do with this number.
Atoms are neutrally charged, which means there has to be an equal number of positive and negative particles. The negative particles of an atom are its electrons, and since our atom has 4 protons, it must also have 4 electrons.
Answer:B
Explanation:
Because chemical energy fuels your body with energy so without it u wont have enough energy to move.
Answer: 4575N
Explanation:
For y component, W = mgcosø
W = 500×9.8cos21
W = 4574.54N
Find the diagram in the attached file
Answer: 11369.46 m/s
Explanation:
We have the following data:
is the mass of the bowling ball
is the velocity of the bowling ball
is the mass of the ping-pong ball
is the velocity of the ping-pong ball
Now, the momentum 
of the bowling ball is:
(1)
(2)
And the momentum 
of the ping-pong ball is:
(3)
If the momentum of the bowling ball is equal to the momentum of the ping-pong ball:
(4)
(5)
Isolating :
(6)
(7)
Finally:
