Atomic structure
⏱ ~3-min readAceMark Guide
What this topic is really about
A neutral oxygen atom has an atomic number of 8, meaning it possesses eight protons and, to balance charge, eight electrons, so the correct count is eight. Choice A suggests six electrons, which actually describes carbon (Z=6); the question explicitly asks for oxygen, making that answer inaccurate.
Sodium has an atomic number of 11, meaning its 11 electrons fill orbitals in order of increasing energy to yield a 1s2 2s2 2p6 3s1 configuration. Option B is incorrect because it contains only 10 electrons, which represents either a neutral neon atom or a sodium cation (Na+).
See the mechanism
A neutral oxygen atom has an atomic number of 8, meaning it possesses eight protons and, to balance charge, eight electrons, so the correct count is eight. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.
An exam-style question, fully explained
The number of electrons in an oxygen atom (Z = 8):
- Identify what the question tests: The number of electrons in an oxygen atom (Z = 8):.
- A neutral oxygen atom has an atomic number of 8, meaning it possesses eight protons and, to balance charge, eight electrons, so the correct count is eight.
- Choice A suggests six electrons, which actually describes carbon (Z=6); the question explicitly asks for oxygen, making that answer inaccurate.
Traps the examiner sets
- Option B is incorrect because it contains only 10 electrons, which represents either a neutral neon atom or a sodium cation (Na+).
Test your recall
Answer each from memory — you'll see instantly whether you're right and why.
Run a focused 10-question mini-mock on Atomic structure and see it stick.
Practice more of this topic →