Illustrated here are three different __________ of carbon. They vary by the number of __________.
A) ions; neutrons
B) ions; electrons
C) molecules; protons
D) isotopes; neutrons
![Illustrated here are three different of carbon They vary by the number of A ions neutrons B ions electrons C molecules protons D isotopes neutrons class=](https://us-static.z-dn.net/files/d4e/dd34a2b4d68fbe0c2d5687658d3ba13a.jpg)