Question

reading comprehension questions
atomic structure & reactivity

1. mr. pauling needs to prepare information about metals for his work on armor prototypes. help him by completing the table about neutral atoms of the listed elements:

elements	number of protons	number of electrons
silicon
beryllium

1. use the table to calculate the number of neutrons in each atom listed.

elements	rounded atomic mass	atomic number	number of neutrons
silicon
beryllium

Explanation:

Step1: Fill protons/electrons for neutral atoms

Neutral atoms have equal protons (atomic number) and electrons.
Aluminum (atomic number 13): 13 protons, 13 electrons
Silicon (atomic number 14): 14 protons, 14 electrons
Beryllium (atomic number 4): 4 protons, 4 electrons

Step2: Calculate neutrons

Neutrons = Rounded atomic mass - atomic number
Aluminum: 27 - 13 = 14
Silicon: 28 - 14 = 14
Beryllium: 9 - 4 = 5

Answer:

1. Aluminum: 13 protons, 13 electrons; Silicon: 14 protons, 14 electrons; Beryllium: 4 protons, 4 electrons
2. Aluminum: 14 neutrons; Silicon: 14 neutrons; Beryllium: 5 neutrons