Chapter 3: The History of the Atom and Periodic Table

increasing atomic number

Periodic table in ordered by_____

groups

Vertical columns called_____

amount of electrons in an elements outer shell

Groups are determined by________

rows

Horizontal columns called_____

Dmitri mendeleev

___left gaps in the periodic table for undiscovered elements

John dalton

_______described atoms as tiny, solid spheres

J.J. Thompson

________created the plum pudding model

weren’t solid spheres

The plum pudding model concluded atoms_______

atom must contain even smaller, negatively charged particles

Plum pudding model showed an_______with electrons stuck in it

ernest rutherford

______fired charged alpha particles at a thing sheet of gold foil

Nuclear model

________tiny, positively charged nucleus at the centre, where most of the mass is concentrated. A ‘cloud’ of negative electrons surrounds this nucleus-so most of the atom is empty space

existence of the proton

_______was proved by james chadwick

electronic structure goes

_______ in the structure 2.8.8.18.18.32.32

a full outer shell

atoms better when they have_______

mass number

is the total amount of neutrons and protons

atomic number

_______is the amount of protons

electrons

protons are the same amount as____

neutral

atom are naturally____

amount of shells

Rows are determined by___