Question

question 13 (3 points) what is the electron arrangement for silicon (si) 2,8,8 2,4,8 2,8,8,6 2,4 2,8,4 question 14 (3 points) if a sodium (na) atom has 13 neutrons, what is its mass number? 22.9 11 24 23 13

Explanation:

Step1: Recall silicon's atomic number

Silicon has an atomic number of 14. The first - electron shell can hold 2 electrons, the second can hold 8 electrons, and the remaining electrons go to the third shell. So the electron - arrangement is 2, 8, 4.

Step2: Recall sodium's atomic number

Sodium (Na) has an atomic number of 11, which means it has 11 protons. The mass number is the sum of protons and neutrons. Given 13 neutrons and 11 protons, the mass number is \(11 + 13=24\).

Answer:

Question 13: 2,8,4
Question 14: 24