The ancient Greek philosopher Demokritos (460-370 BCE) thought that matter was made up of millions of tiny, uncuttable pieces of that same matter.
what atomic model is this and who made it?
A) plum pudding model
B) JJ Thomson
what experiment does this diagram suggest?
A) alpha particle experiment
Who discovered the nuclear atom, a small, positively-charged nucleus surrounded by empty space and then a layer of electrons to form the outside of the atom?
Rutherford
Who suggested that electrons orbit the nucleus in fixed shells?
Neils Bohr
Who discovered the neutron?
James Chadwick
Most alpha particles going through the gold foil tells us atoms are mostly empty space.
What do A, Z and X stand for?
A: mass number
Z: atomic number
X: symbol
Atoms with different amount of neutrons but same number of protons are called isotopes.
When an atom loses or gains electrons, this is atom is called an ion.