Question

atomic structure & reactivity
1 mr. pauling needs you 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
aluminum
silicon
beryllium
2 use the table below to calculate the number of neutrons in each atom listed.
elements rounded atomic mass atomic number number of neutrons
aluminum
silicon
beryllium

Explanation:

Step1: Recall atomic - structure facts

In a neutral atom, the number of protons is equal to the number of electrons and is equal to the atomic number.

Step2: Find atomic numbers

The atomic number of aluminum (Al) is 13, so the number of protons and electrons in aluminum is 13. The atomic number of silicon (Si) is 14, so the number of protons and electrons in silicon is 14. The atomic number of beryllium (Be) is 4, so the number of protons and electrons in beryllium is 4.

Step3: Recall neutron - calculation formula

The number of neutrons = Rounded atomic mass - Atomic number.

Step4: Find neutron numbers

The rounded atomic mass of aluminum is 27 and its atomic number is 13, so the number of neutrons is $27 - 13=14$. The rounded atomic mass of silicon is 28 and its atomic number is 14, so the number of neutrons is $28 - 14 = 14$. The rounded atomic mass of beryllium is 9 and its atomic number is 4, so the number of neutrons is $9 - 4=5$.

Answer:

Elements	Number of Protons	Number of Electrons
Silicon	14	14
Beryllium	4	4

Elements	Rounded Atomic Mass	Atomic Number	Number of Neutrons
Silicon	28	14	14
Beryllium	9	4	5