Neco 2025 Chemistry Question 1

Practice essay / theory question 1 from the 2025 Neco Chemistry examination. This question covers Atomic Structure .

Neco 2025 Chemistry Essay / Theory

Topic: Atomic Structure

Question 1 NECO • 2025 • CHEMISTRY • essay

The diagram shows a Bohr model of a sodium (Na) atom. The nucleus contains 11 protons and the mass number is 23. The electrons are distributed in three shells: the K‑shell contains 2 electrons, the L‑shell contains 8 electrons and the M‑shell contains 1 electron.

Question Parts

( a )

State the number of protons, neutrons and electrons present in a neutral sodium atom.

( b )

Write the ground‑state electron configuration of sodium using the notation 1s, 2s, 2p, 3s …

( c )

Explain, with reference to the diagram, why sodium readily loses one electron to form the Na⁺ ion. State one physical property that changes when Na becomes Na⁺.

( d )

The first ionisation energy of sodium is 496 kJ mol⁻¹. Calculate the amount of energy required to remove one outermost electron from a single sodium atom. Express your answer in joules (J) in scientific notation.

Detailed Solution & Marking Scheme

Get the step-by-step solution, key points required by examiners and detailed marking guidance through the Edcrib AI Tutor.

Reveal Answer

About This Question

This is Neco 2025 Chemistry Question 1. It is one of the essay questions from the 2025 Neco Chemistry examination.

The question covers Atomic Structure .

View More Neco 2025 Chemistry Questions More Neco Practice Questions Back to Questions

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows

Chat with Support