Atomic Structure - Fundamental particles

Question 1

What did Democritus discover?

Answer 1

An atom is the smallest indivisible particle

Question 2

John Dalton

Answer 2

• described atoms as solid different sized spheres which make up different elements

Question 3

J.J Thomson

Answer 3

Concluded that an atom must contain even smaller negatively charged particles called electrons
“Plum-pudding model” - atoms are a ball of positive charge with electrons evenly distributed

Question 4

Rutherford

Answer 4

Did the alpha scattering experiment
Atoms were deflected meaning that’s there is a positive nucleus surrounded by a cloud of electrons.

Question 5

Neil Bohr

Answer 5

Electrons surrounded positive nucleus in fixed orbitals - nuclear model.

Question 6

James Chadwick

Answer 6

Discovered neutrons and protons in nucleus with electrons surrounding shells
Discovered mass

Question 7

What is the mass of protons neutrons and electrons?

Answer 7

1
1
1/1840

Question 8

What is the charge of p,n,e

Answer 8

1
0
-1

Question 9

What overall charge does an atom have?

Answer 9

overall positive charge

Question 10

What is the atomic number?

Answer 10

Number of protons in nucleus of atom (Z)

Question 11

What is the mass number?

Answer 11

Total number of protons and neutrons in the nucleus o an atom and has the symbol A

Question 12

How can we calculate neutrons in the atom?

Answer 12

Number of neutrons = mass number - atomic number