Which of the following statements about neutrons is true
a : neutrons make an atom more stable
b: isotopes if an element have the same number of neutrons
c: the number of neutrons in an atom determines what element it is
d: neutrons have much less mass than protons or electrons

The answer is A: neutrons help make an atom more stable.

Neutrons do not have a charge, and they weigh about the same as a proton. Neutrons make an atom more stable because they hold the protons together. Without neutrons, the protons would separate from each other.

The answer is A: neutrons help make an atom more stable.

n+h→nh3

we must remember that nitrogen and hydrogen are both diatomic molecules in their standard gas form. this adjusts the equation to

n2+h2→nh3

now we need to adjust coefficients in order to balance the atoms on each side of the equation. currently we have 2 atoms of nitrogen and 2 atoms of hydrogen on the reactant side and 1 atom of nitrogen and 3 atoms of hydrogen on the product side.

we can balance the hydrogens by placing a coefficient of 2 in front of ammonia and a coefficient of 3 in front of the hydrogen.

n2+3h2→2nh3

this gives us 6 hydrogen on each side and coincidentally the nitrogens now equal 2 on each side.