How would u solve the first one? i’m confused.

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have

This active feature of earth's crust in building mountain ranges as well as islands. this feature is a a) cavern. b) earthquake. c) mountain. d) volcano.

Which of the following happens during cell division? (a) energy is created (b) waste is eliminated (c) carbon dioxide is released (d) damaged cells are replaced