Here's how to break down the number of atoms in 2C2H6:

* The coefficient: The "2" in front of the formula indicates that we have two molecules of C2H6.

* The subscripts: The "2" in C2H6 indicates that each molecule has 2 carbon atoms. The "6" indicates that each molecule has 6 hydrogen atoms.

Calculation:

* Carbon: 2 molecules * 2 carbon atoms/molecule = 4 carbon atoms

* Hydrogen: 2 molecules * 6 hydrogen atoms/molecule = 12 hydrogen atoms

Therefore, 2C2H6 contains 4 carbon atoms and 12 hydrogen atoms.