1.1 Atomic structure

Question 1

What has evolved over time?

Answer 1

Knowledge and understanding of atomic structure has evolved over time

Question 2

What does an atom consist of?

Answer 2

An atom consists of a nucleus containing protons and neutrons surrounded by electrons

Question 3

Mass number =

Answer 3

protons + neutrons (A)

Question 4

Atomic number =

Answer 4

number of protons/ electrons (Z)

Question 5

Proton (relative charge + relative mass)

Answer 5

+1 , 1

Question 6

Neutron (relative charge + relative mass)

Answer 6

0 , 1

Question 7

Electron (relative charge + relative mass)

Answer 7

-1 , 1/2000

Question 8

Describe the nucleus of the atom?

Answer 8

very small - consists of only protons and neutrons

Question 9

Describe the activity of the electrons?

Answer 9

orbit the nucleus in shells and take up most space in the atom

Question 10

What is the charge of the nucleus?

Answer 10

neutral because protons = electrons

Question 11

What are ions?

Answer 11

have different number of electrons and protons

Question 12

What are isotopes?

Answer 12

elements with same number of protons (same element) but different numbers of neutrons (different mass)

Question 13

1803: John Dalton

Answer 13

atoms are indivisible spheres and each element is a different sphere

Question 14

1897: JJ Thompson

Answer 14

ELECTRON DISCOVERED
atom not solid, made up of other particles: plum pudding model

Question 15

1909: Ernest Rutherford

Answer 15

NUCLEUS DISCOVERED
also nucleus is very small, positively charged so atom is mainly empty space

Question 16

How did Rutherford prove this?

Answer 16

alpha particle scattering experiment: fired alpha particles at 1 atom thick gold leaf and most went through (empty space), some reflected back (most of mass concentrated in nucleus) (nucleus is positively charged)