C1 Flashcards
what is the top number in an element
mass number
what is the bottom number in an element
proton number
what is the mass of an electron
negligible
what are the rules to balancing equations
same number of atoms in each side of the arrow. Only use whole numbers. Only add whole numbers in
What is a filtrate
a liquid collected at the bottom of the beaker
What does miscible mean
liquids that dissolve in each other
what is an isotope
an atom with the same number of protons but a different number of neutrons
what is an ion
a charged atom or molecule
what does Li+ mean
Lithium has lost electrons
What does Li- mean
Lithium has gained electrons
What does distillation do
Separates a solvent from a solution
What does filtration do
obtains a residue from the solution
What did John Dalton discover
He thought that atoms were tiny hard spheres. He suggested that each element had its own atom. He believed that they couldn’t divide or split, but that they could rearrange with other atoms
What did Ernst Rutherford discover
The positive charge must be concentrated in a tiny spot in the centre of the atom otherwise the positive particles could never be repelled back. He said electrons must be orbiting around a nucleus which must contain a lot of protons
How did Ernst Rutherford discover this?
They fired positively charged particles at a thin piece of gold. They expected them to go straight threw but some of them bounced back, disproving Thompson plum pudding theory.
