Question

PLEASE HURRY WILL MARK BRAINLIEST 

Answer 1

Answer:

C. Combined number of neutrons and protons.

Explanation:

The number is the atomic mass. Atomic mass is neutrons + protons.

And I got it right on the quiz on E2020.

Answer 2

Answer:

12 Neutrons

1 Valence Electron

23 ions [11 Protons and 12 Neutrons]

22 ions [11 Electrons and Protons]

Explanation:

To find the number of neutrons in an element, you simply take its atomic number and deduct that from the atomic mass [round if necessary]. There is one valence electron because according to the Periodic Table of Elements, the first three energy levels can fit 2 - 8 electrons:

1st Energy Level → 2 Electrons

2nd Energy Level → 8 Electrons

3rd Energy Level → 8 Electrons

4th Energy Level → 18 Electrons

5th Energy Level → 18 Electrons

6th Energy Level [Lanthanide Series] → 32 Electrons

7th Energy Level [Actinide Series] → 32 Electrons

So, as you can see, 2 + 8 gives you 10. So from there, we already filled up 2 energy levels. Now going to the third one will leave us with only one electron left over. That is where that valence electron is.

** I encourage you to write this down in your Chemistry notebook somewhere, so you can keep this stored in your memory at all times. There are some pointers in the answer as well. Copy that.

I am joyous to assist you anytime.