Chemistry 1a
The smallest part of an element that can exist
What is an atom?
10-10m
What is the radius of an atom?
Atoms with different numbers of neutrons
What is an isotope?
Small, dense and positively charged
What is the nucleus like?
1/2000th the mass of a proton
What is the mass of an electron?
A charged atom
What is an ion?
10-14m
What is the radius of a nucleus?
Two or more different atoms/compounds not chemically combined together
What is a mixture?
It has a mass of 1 but no charge
What is a neutron?
The plum pudding model
They jump up an energy level
What happens to electrons when they absorb radiation?
1 000 000 000 in 1 metre
What is a nanometre?
It was how the nucleus was discovered
What was the alpha scattering experiment?
It has a negative charge and a tiny mass
What is an electron?
James Chadwick
Who found the neutron?
Who was Neils Bohr?
Also called the atomic number
What is the proton number?
Mostly empty space
What makes up most of an atom?
Mercury with over 50 different ones
Which element has the most isotopes?
Always positive because of the protons
What is the charge on the nucleus
Electrons then protons then neutrons
What order were the particles discovered?
Gold
What metal was used in the alpha scattering experiment?
They are made up of 2 protons and 2 neutrons
What is an alpha particle?
What are electron shells?
20 years
How long did scientists spend looking for the neutron?