Understanding Isotopes

•Given a nuclear symbol, what does the top left number represent?

•Given a nuclear symbol, what does the bottom left number represent?

What does the number after the hyphen represent in Li-7?

•Boron consists of two isotopes, ¹⁰₅B and ¹¹₅B, what accounts for the difference in the numbers after the hyphen?

How many neutrons does ²⁵₁₂Mg have?

The average atomic mass is based on the mass of all the __________ of the element.

To calculate the average atomic mass you must first multiple what two numbers?

Nitrogen-14 has a percent abundance of 99.636% and Nitrogen-15 has a percent abundance of 0.364%. What is the average amount mass for Nitrogen.