The scientist lother mayer was the first to organize the elements to show a connection between the elementsthat can be observed and? (two answers)
1) atomic mass
2) properties
3) groups
4) intervals
5) atomic mass

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%).

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.