Bonding & StructureIntroduction

Why Can't You Melt Salt on a Kitchen Stove?

Part of Ionic CompoundsGCSE Chemistry

This introduction covers Why Can't You Melt Salt on a Kitchen Stove? within Ionic Compounds for GCSE Chemistry. Revise Ionic Compounds in Bonding & Structure for GCSE Chemistry with 20 exam-style questions and 20 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 1 of 12 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 1 of 12

Practice

20 questions

Recall

20 flashcards

📖 Why Can't You Melt Salt on a Kitchen Stove?

Here's a puzzle: sugar melts easily when you heat it — it turns into caramel. But salt? You could put salt on the hottest stove setting and wait all day, and it would just sit there. What makes salt so incredibly resistant to melting? The answer lies in understanding what ionic compounds really look like at the atomic level.
🏗️ The 3D LEGO Analogy

An ionic lattice is like a 3D LEGO tower where every piece is glued to its neighbours. Imagine building with red and blue LEGO bricks where every red brick must touch only blue bricks and vice versa. The glue (electrostatic attraction) holds them so strongly that you'd need to heat the whole structure to over 800°C to break it apart. That's why ionic compounds have such high melting points!

When we talked about ionic bonding, we focused on ONE sodium giving ONE electron to ONE chlorine. But here's what really happens when you make sodium chloride: you don't make billions of tiny NaCl "molecules" floating around. Instead, you create something much more impressive — a giant ionic lattice.

Imagine building with LEGO, but instead of random stacking, every single piece must alternate in a perfect 3D pattern. Each Na⁺ ion is surrounded by Cl⁻ ions, and each Cl⁻ is surrounded by Na⁺ ions. Not just next to each other — but above, below, in front, behind, left, and right. This pattern repeats BILLIONS of times in every direction. The result is a crystal — a rigid, geometric structure held together by countless electrostatic attractions.

This is why salt is hard to melt. To melt something, you need to break the structure apart. But in a giant ionic lattice, you're not breaking just one or two bonds — you're fighting against BILLIONS of strong electrostatic attractions all at once! That takes an enormous amount of energy. Salt doesn't melt until 801°C — hot enough to glow bright red!

And here's the electricity puzzle: Salt is made of charged ions, yet solid salt doesn't conduct electricity. Put two wires into a pile of salt, connect it to a battery — nothing happens. But dissolve that salt in water, and suddenly electricity flows! Why? In solid salt, the ions are locked in fixed positions — they can't move to carry the charge. When you melt or dissolve salt, the lattice breaks apart and the ions become free to move. Moving charges = electric current!

Keep building this topic

Read this section alongside the surrounding pages in Ionic Compounds. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Ionic Compounds

What type of structure is found in all ionic compounds?

  • A. Giant ionic lattice
  • B. Simple molecular
  • C. Giant covalent
  • D. Metallic lattice
1 markfoundation

Explain why magnesium oxide conducts electricity when it is molten but not when it is solid.

2 marksstandard

Quick Recall Flashcards

What is a giant ionic lattice?
A regular 3D arrangement of alternating positive and negative ions extending in all directions
Why are ionic compounds brittle?
Force shifts ion layers, bringing like charges together — they repel and the structure shatters

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