How do carbo-12 and carbon -14 differ

The numbers refer to the mass of each carbon atom.  

Since the atoms are all Carbon, the number of protons in each atom is always the same ... if the number of protons changed, then you'd have an atom of something else, not Carbon.  The only way the atomic mass can change and still be an atom of the same element is by adding or removing NEUTRONS.

Carbon-14 has two more neutrons in the nucleus of its atoms than Carbon-12 has.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2