We can represent atoms by listing the number of protons, neutrons, and electrons: for example,
2p?; 2n°; 2e? for helium. Which of the following represents the 18O isotope of oxygen?
A) 6p?, 8n°, 6e?
B) 8p?, 10n°, 8e?
C) 9p?, 9n°, 9e?
D) 7p?, 2n°, 9e?
E) 10p?, 8n°, 9e?
Answer: B