H Chem: Chapter 4 - Isotopes

$$\ _{\ \ 7}^{14}\ N\ ^{-3}$$  

How many protons?

How many neutrons?

How many electrons?

Carbon has two isotopes.  Carbon-12 is 98.89% abundant and carbon-13 is 1.11% abundant.  Carbon-12 has a mass of 12.000000 amu and carbon-13 has a mass of 13.00335 amu.  What is the average atomic mass?

The element chlorine has two common isotopes, chlorine-35 (75.63% abundant) and chlorine-37 (24.37% abundant).  The atomic masses of these two isotopes are 34.968 amu and 36.956 amu, respectively.  What is the average atomic mass of the element chlorine?

Lithium has an average atomic mass of 6.941 amu. Lithium has two common isotopes lithium-6 and lithium-7. If the atomic masses of these two isotopes are 6.0151 amu and 7.0160 amu, respectively. What are the percentage abundances of each of these isotopes?