Beryllium has an atomic number of 4. How many neutrons does the isotope beryllium-9 have?(1 point)

Question

Responses

5
5

9
9

4
4

13
13

Answer 1

To find the number of neutrons in an isotope, you can use the formula:

\[ \text{Number of neutrons} = \text{Mass number} - \text{Atomic number} \]

For beryllium-9:

• The mass number is 9.
• The atomic number (which is the number of protons) is 4.

Now, substituting the values:

\[ \text{Number of neutrons} = 9 - 4 = 5 \]

Therefore, the correct response is 5.