Respuesta :

Answer:

128 neutrons

Explanation:

How many neutrons are there in 8 molecules of [tex]^{19} _9 F_2[/tex]?

Step 1: Calculate the number of neutrons in 1 atom of F.

The atomic number (z) of F is 9 and its mass number (A) is 19. We can calculate the number of neutrons using the following expression.

n⁰ = A - Z = 19 - 9 = 10

Step 2: Calculate the number of neutrons in 1 molecule of F₂.

1 molecule of F₂ contains 2 atoms of F. The number of neutrons in  1 molecule of F₂ is:

(8 n⁰/1 atom F) × (2 atom F/1 molecule F₂) = 16 n⁰/1 molecule F₂

Step 3: Calculate the number of neutrons in 8 molecules of F₂

8 molecule F₂ × 16 n⁰/1 molecule F₂ = 128 n⁰