Question

seven sulfur dioxide molecules
express your answer as an integer.

atoms

Explanation:

Step1: Determine atoms in one $SO_2$

One $SO_2$ molecule has 1 S atom and 2 O atoms, so total atoms per molecule: $1 + 2 = 3$.

Step2: Calculate atoms in 7 molecules

Multiply atoms per molecule by number of molecules: $7\times3 = 21$.

Answer:

21