AQA · Chemistry · 8462
GCSE Chemistry (AQA): States of Matter
Topic 2 — Bonding, Structure & Properties of Matter. Generated from the caption track of Cognito's lesson video "GCSE Chemistry - States of Matter & Changing State"; each card deep-links to the moment in the video it came from. Lesson 2.12 of Cognito's AQA GCSE Combined Science (Trilogy) and Chemistry course (Higher tier), filed under AQA Chemistry 8462. Teaching by Cognito — https://cognitoedu.org/coursesubtopic/c2-gcse-aqa-h-c_2.12.
12 flashcards · Free to study · No account needed
Study this deck
Preparing your cards…
All questions and answers
Read through the full deck, or practise recalling each answer above.
Why does a liquid have a definite volume but no definite shape?
Show answer
Weak forces still hold the particles fairly compact, but the particles are free to move past each other, so the liquid flows to fit its container.
How do particles in a solid move?
Show answer
They vibrate about fixed positions; they cannot move past one another.
In liquids there are only ? forces of attraction between the particles, so they can move around randomly.
Show answer
weak
Give two limitations of the simple particle model.
Show answer
It treats particles as solid inelastic spheres (really they are atoms, ions or molecules), and it ignores the forces between particles.
What is meant by the 'random motion' of gas particles?
Show answer
Particles travel in straight lines in any direction and are randomly deflected when they collide with walls or other particles — they do not swerve.
Why do gases have neither a definite shape nor a definite volume?
Show answer
The forces of attraction between gas particles are very weak, so the particles move freely and spread out to fill any container.
Why does cooling a gas enough cause it to condense?
Show answer
The particles lose energy until they can no longer overcome the forces of attraction between them, so bonds form and a liquid results.
What happens to the forces between liquid particles as the liquid is heated?
Show answer
Particles gain energy and move faster, which weakens the forces holding them together until, at the boiling point, the bonds break and the liquid becomes a gas.
In particle theory, how is each particle modelled?
Show answer
As a small, solid, inelastic sphere.
Why do solids keep a definite shape and volume?
Show answer
Strong forces of attraction hold the particles close together in fixed positions in a regular lattice.
Define the melting point of a substance.
Show answer
The temperature at which particles have enough energy to break free of the forces holding them in fixed positions, so the solid becomes a liquid.
What happens when a gas in a fixed, non-expandable container is heated?
Show answer
The pressure increases, because the faster-moving particles collide with the walls more often and harder.
Want to create your own cards? Create a free account. AI generation uses credits.