There are three naturally occurring isotopes of nitrogen as follows:

nitrogen-14 with a 95% abundance

nitrogen-15 with a 3% abundance

nitrogen-16 with 2% abundance

part a (3points): explain at least three things that the isotopes of nitrogen have in
common.

part b (2 points): explain at least two differences between isotopes of nitrogen.

part c (2 points): which isotope of nitrogen is going to have the greatest affect on
the average atomic mass of nitrogen? give supporting evidence for your answer.

part d (1 point): explain why nitrogen-14 and oxygen-14 are not isotopes of each
other.

See explanation

Explanation:

a) Isotopes are variants of one chemical element which (such as Nitrogen in this case). Those variants differ in neutron number and nucleon number.

This is also the reason why they have different masses. Isotopes are different physically to their original atoms.

b) All isotopes of a given element have the same number of protons and electrons. All the isotopes have the same atomic number as the original element. Isotopes are almost the same chemically.

c) The 14 in the name of Nitrogen-14, means  it has a mass of 14u ( while Nitrogen 15 has a mass of 15 u). Nitrogen-14 will have the greatest affect on the average atomic mass, this because of the 95% abundance.

Nitrogen has an average atomic mass of 14.0067 u. This is the closest to 14, what shows nitrogen-14 has the biggest affect.

The average atomic mass is calculated as following: 14*0.95 +15*0.03 + 16*0.02 =14.07 u

d) Both are isotopes, but of another element. They both have a mass of 14 u. Bu they have a different number of neutrons: Oxygen-14 has 6 neutrons and 8 protons while Nitrogen-14 has 7 neutrons and 7 protons. This means oxygen-14 and nitrogen-14 are not isotopes, since isotopes do have the same number of neutrons.

the answer is 75.0%.