What are the three states of matter?
solid
liquid
gas
What is a solid?
the particles are arranged and close together
What is a liquid?
the particles are randomly arranged and close together
What is a gas?
the particles are randomly arranged and far apart
What is a chemical change?
what is created is chemically different to what is reacted
What is a physical change?
changing in state eg. melting
What is a limitations?
the attraction and spaces between particles
What did John Dalton do?
atoms make up all substances
What did Tomson do?
the plum pudding model
What did Rutherford do?
that atoms have a nucleus and the proton
What did Bohr do?
electrons are in shells
What is an atom?
negatively charged electrons surrounding a positive nucleus
What is smaller molecules or atoms?
atoms as they make up molecules
What is the relative charge and mass of a proton?
charge +1
mass 1
What is the relative charge and mass of a neutron?
charge 0
mass 1
What is the relative charge and mass of an electron?
charge -1
mass 1/1836
What is an atomic number?
number of protons (electrons)
What is an isotope?
an element with different neutrons but the same protons
What is the mass number?
protons + neutrons
What is an ion?
an atom with a charge
How do you find the number of protons?
the same as the atomic number
How do you find the number of neutrons?
mass number - atomic number
How do you find the number of electrons?
number of protons