list the numbers of each atom in all the formulas above: h c

Explanation:

Step1: Count H - atoms in first formula

In the first formula $\text{CH}_3\text{CH}_3$, there are 3 H - atoms in each $\text{CH}_3$ group, so a total of 6 H - atoms. In the second formula $\text{H}_3\text{C}-\text{CH}_2-\text{CH}_3$, there are 3 H - atoms in the $\text{H}_3\text{C}$ and $\text{CH}_3$ groups and 2 H - atoms in the $\text{CH}_2$ group, so $3 + 2+3=8$ H - atoms. In the molecular - model, count the white balls (representing H - atoms), there are 18. In total, $6 + 8+18 = 24$ H - atoms.

Step2: Count C - atoms in first formula

In the first formula $\text{CH}_3\text{CH}_3$, there are 2 C - atoms. In the second formula $\text{H}_3\text{C}-\text{CH}_2-\text{CH}_3$, there are 3 C - atoms. In the molecular - model, count the black balls (representing C - atoms), there are 6. In total, $2+3 + 6=11$ C - atoms.

Answer:

H: 24 C: 11