This one too, please? (3rd time)

I need explanation for your answers, even though it's multiple choices, I still need your explanation for it.

DUE TOMORROW!

If your answer is NONSENSE it will be deleted as soon as possible!

But if your answer is CORRECT, HELPFUL, HAS AN EXPLANATION, I'll chose your answer as the BRAINLIEST ANSWER!​

1, group 1

2 group 7

3 group 2

4 D

5 B

6 A

7. A 1

8. C 17

9. B 2

10. (d) C and D

11. (b) reactivity

12. (a) corrosion

13. (c) activity series

Explanation:

7. , 8, and 9,

Group 1 elements are named as alkali metals

Group 2 elements are known as alkaline earth metals

group 17 metals are known as halogens

10.

Na and Xe have one valency whereas the other two elements have variable valency which is a property of transition metals so the answer is (d) C and D

11.

It;s the definition of reactivity

12.

Definition of corrosion

13.

definition of activity series

which

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements