The mass of an atom comes from the protons and neutrons that is found in the nucleus. The number of protons is the atomic number of an element. To find the number of neutrons, subtract the atomic number from the mass of an atom. For example, sodium’s atomic number is 11. This will tell us that sodium has 11 protons in it. The atomic mass of sodium is 23. So subtract 23 form 11 gives us 12. Therefore, there are 12 neutrons in sodium.
Answer:
True
Explanation:
Pre-questioning may help a reader focus on information s/he hopes to find in the reading selection.
Answer:
2.5 s, 5 m
Explanation:
The equations for the horizontal and vertical position of Lukalu are:

we can find the time it takes her to reach the ground by requiring that the vertical position becomes zero:
y(t) = 0
So we find:

The horizontal distance of Lukalu instead will be given by the equation for the horizontal position, substituting t = 2.5 s:

B. The answer is most likely B