Science Yr 8 EOY exam revision - Matter

Chemical reaction

when atoms of the reactants rearrange

What does the conservation of mass state

the mass of the reactants of a chemical reaction is the same as the mass of the products

Internal energy

the energy that a substance has

Are physical reactions reversible?

yes

What is an Atom?

An atom is a pure element like gold, iron or helium

What is a molecule?

A molecule consists of multiple atoms attached together like how water is H20

What is the word equation for density?

Density = mass / volume

Insoluble

will not dissolve

soluble

will disolve

solute

the substance that dissolves

solvent

the substance that dissolves the solute

solution

what is left after the solute has dissolved into the solvent

saturated solution

a solution to which you can’t add more of the solute

Brownian motion

describes the random motion of gas particles

diffusion

the movement of particles as they spread out from an area of high concentration to an area of low concentration

What can speed up the rate of diffusion?

A high temperature and a high concentration gradient

What is mass

how much matter there is in an object