ATOM

Question 1

John Dalton 1800

Answer 1

Tiny spheres that could not be divided

Question 2

Jj Thompson 1890

Answer 2

Electron discovered.

Plum pudding model - spheres of positive charge with negative charges spread evenly through

Question 3

E.Rutherford, Geiger and Marsden 1908-1913

Answer 3

Alpha particle scattering experiment.

Nuclear model - mass of atom concentrated in a charged nucleus, with orbiting electrons

Question 4

Niels Bohr 1914

Answer 4

Electrons orbit nucleus at specific distances in fixed energy levels (shells). Energy given out when electrons change level

Question 5

Later

Answer 5

Positive charge of nucleus could be subdivided into particles of positive charge - protons

Question 6

James Chadwick 1932

Answer 6

Provided evidence for the existence of neutrons within the nucleus

Question 7

Mass of a proton

Answer 7

1

Question 8

Mass of a neutron

Answer 8

1

Question 9

Mass of an electron

Answer 9

Very small

Question 10

Charge of a proton

Answer 10

+1

Question 11

Charge of a neutron

Answer 11

0

Question 12

Charge of an electron

Answer 12

-1

Question 13

Location of a proton

Answer 13

Nucleus

Question 14

Location of a neutron

Answer 14

Nucleus

Question 15

Locations of electrons

Answer 15

Shells

Question 16

Where’s most of the mass found in an atom

Answer 16

The nucleus

Question 17

Number of protons =

Answer 17

Atomic number

Question 18

Atomic number =

Answer 18

Number of protons

Question 19

Why do atoms have no overall electrical charge?

Answer 19

Because the number of positive protons equals the number of negative electrons

Question 20

Mass number =

Answer 20

Number of protons and neutrons

Question 21

Number of protons and neutrons =

Answer 21

Mass number

Question 22

Number of protons =

Answer 22

Atomic number

Question 23

Atomic number =

Answer 23

Number of protons

Question 24

Mass number - atomic number =

Answer 24

Number of neutrons

Question 25

Number of neutrons =

Answer 25

Mass number - atomic number