Final answer:
The total number of atoms in 3 molecules of K2SO4 is 21 atoms, which includes 6 potassium, 3 sulfur, and 12 oxygen atoms.
Step-by-step explanation:
The student asked how many total atoms make up the molecule 3K2SO4. In the compound K2SO4, there are 2 potassium (K) atoms, 1 sulfur (S) atom, and 4 oxygen (O) atoms. Therefore, in one molecule of K2SO4, there is a total of 7 atoms. As the student is asking for 3 molecules, you simply multiply the number of atoms in one molecule by 3. That gives you: 2 K atoms x 3 molecules = 6 K atoms, 1 S atom x 3 molecules = 3 S atoms, and 4 O atoms x 3 molecules = 12 O atoms. Adding these up gives you a total of 21 atoms in 3 molecules of K2SO4.