3. A forensic scientist analyzes a sample for sodium arsenate, Na2AsO4(s), a source of arsenic. Calculate the percent arsenic in sodium arsenate.

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).