Question

We can represent atoms by listing the number of protons, neutrons, and electrons −
for example, 2p+,2n0,2e−
for helium. Which of the following represents the 18O
isotope of oxygen?

8p+,10n0,8e−

10p+,8n0,9e−

7p+,2n0,9e−

9p+,9n0,9e−

Answers

GPT-4o mini
The isotope notation for oxygen-18 (\(^{18}\text{O}\)) indicates that this isotope has a mass number of 18. The atomic number of oxygen is 8, which means it has 8 protons.

To find the number of neutrons in \(^{18}\text{O}\), we can use the formula:
\[
\text{Number of neutrons} = \text{Mass number} - \text{Number of protons}
\]
Thus, the number of neutrons in \(^{18}\text{O}\) is:
\[
18 - 8 = 10 \text{ neutrons}
\]

Furthermore, since this is a neutral atom of oxygen, the number of electrons will equal the number of protons, which is 8.

Putting this all together, the representation for the oxygen-18 ( \(^{18}\text{O}\)) isotope is:
\[
8p^+, 10n^0, 8e^-
\]

Therefore, the correct representation among the given options is:
**8p+, 10n0, 8e−**.