topic 3- atomic structure

Question 1

What is the nucleus made up of?

Answer 1

• protons

- neutrons

Question 2

Who discovered the first solid atom model, what was it and when?

Answer 2

Dalton discovered the first solid atom model in 1803: all atoms of an element are identical; different elements have different atoms

Question 3

Who discovered the electron and when?

Answer 3

Thomson in 1897

Question 4

Who discovered the plum pudding model, what was it and when?

Answer 4

Thomson discovered the plum pudding model in 1904, atoms are spheres of positive charge with negative electrons dotted around inside

Question 5

Who discovered the solar system model, what was it and when?

Answer 5

Rutherford in 1911, it showed atoms have a positive nucleus which is surrounded by negative electrons in orbits.

Question 6

Who discovered the electron shell model, what was it and when?

Answer 6

Bohr in 1913, it showed electrons occupy shells or energy levels around the nucleus

Question 7

Who and when was the proton discovered?

Answer 7

Rutherford in 1918

Question 8

Who and when was the neutron discovered?

Answer 8

In 1932, by Chadwick

Question 9

Relative charge of a proton

Answer 9

+1

Question 10

Relative charge of a neutron

Answer 10

0

Question 11

Relative charge of an electron

Answer 11

-1

Question 12

Relative mass of a proton

Answer 12

1

Question 13

Relative mass of a neutron

Answer 13

1

Question 14

Relative mass of an electron

Answer 14

1/1836

Question 15

Describe the structure of an atom

Answer 15

• central nucleus containing protons and (usually) neutrons

- surrounded by electrons on shells

Question 16

Explain why atoms are electrically neutral overall

Answer 16

Atoms contain equal numbers of protons and electrons. Protons have a +1 charge and electrons have a -1 charge therefore the charges balance out.