C1 Flashcards
What is the force between the particles in a solid?
A strong force, holding them in fixed positions and a regular lattice arrangement
Why do all solids keep a definite shape and volume?
The particles don’t move from their fixed positions
What are particles in a solid constantly doing, and what happens if you heat a solid?
They are constantly vibrating about their positions - the hotter a solid becomes, the more it vibrates
What happens when a solid is heated/vibrates more?
It expands slightly
What is the force between the particles in a liquid?
There is some force of attraction between the particles, allowing them to freely move past each other but they do tend to stick together
How do liquids behave in a container?
They don’t keep a definite shape and so flow to fill the bottom of their container. However, they keep the same volume.
What is the force between the particles in a gas?
There is no force of attraction between the particles, meaning that they are free to move. They travel in straight lines and only interact when they collide.
How do gases behave in a container?
They don’t keep a definite shape or volume and will always fill any container.
What do gas particles do when they bounce off of the walls of their container?
They exert pressure
What happens when a gas is heated?
The particles, which are moving constantly, move faster. They either expand when heated, or their pressure increases.
What are the issues with the “particle theory” model?
The model doesn’t show forces between particles.
What is a physical change?
When a substance changes from one state of matter to another. No new substances are made - the original chemicals just change state.
What is a chemical change?
Bonds between atoms break and atoms change places - the atoms from the substances you start off with (reactants) rearrange themselves to form different chemicals (products).
How did John Dalton describe atoms?
He described them as solid spheres and said that different spheres made different elements.
What did JJ Thomson’s experiments and measurements show him?
His measurements of charge and mass showed that an atom contained small, negatively charged particles - electrons.