Atomic structure

Question 1

Which atomic model does this show?

Answer 1

Plum pudding model

Question 2

Who developed the plum pudding model?

Answer 2

JJ Thompson

Question 3

Describe John Dalton’s model of the atom.

Answer 3

Atoms are tiny spheres that cannot be divided.

Question 4

Describe the plum pudding model of the atom.

Answer 4

The atom is a ball of positive charge with negative electrons embedded in it.

Question 5

Who carried out the alpha particle scattering experiment?

Answer 5

Ernest Rutherford

Question 6

Describe the alpha particle scattering experiment.

Answer 6

• Positively charged alpha particles were fired at thin gold foil
• Most alpha particles went straight through the foil
• A few alpha particles were scattered in different directions

Question 7

Who developed the nuclear model?

Answer 7

Rutherford

Question 8

Describe the nuclear model.

Answer 8

• The mass of an atom is concentrated in the centre, the nucleus
• The nucleus is positively charged

Question 9

Who developed the theory that electrons orbit the nucleus in shells?

Answer 9

Niels Bohr

Question 10

What is the charge on a proton?

Answer 10

+1 (positive)

Question 11

What is the charge on an electron?

Answer 11

-1 (negative)

Question 12

What is the charge on a neutron?

Answer 12

0 (neutral)

Question 13

Which two subatomic particles are found in the nucleus?

Answer 13

• Protons

- Neutrons

Question 14

What is the relative mass of a proton?

Answer 14

1

Question 15

What is the relative mass of a neutron?

Answer 15

1

Question 16

What is the relative mass of an electron?

Answer 16

Almost 0 (negligible)

Question 17

What is the atomic number?

Answer 17

The number of protons in an atom

Question 18

Why does an atom have no overall charge?

Answer 18

An atom has equal numbers of protons (positive) and electrons (negative)

Question 19

What is the atomic number of sodium?

Answer 19

11

Question 20

How many protons are in an atom of oxygen?

Answer 20

8

Question 21

What does the mass number represent?

Answer 21

The total number of protons and neutrons in an atom

Question 22

How many neutrons does this sodium atom have?

Answer 22

12 neutrons

Question 23

How can you calculate the number of neutrons an atom has?

Answer 23

Mass number - atomic number

Question 24

What is an isotope?

Answer 24

Atoms of the same element with different numbers of neutrons

Question 25

Why do all isotopes of the same element have the same properties?

Answer 25

Because they have the same number of electrons

Question 26

What is the relative atomic mass?

Answer 26

The mean relative mass of the atoms of the different isotopes of an element

Question 27

75% of chlorine atoms have a mass number of 35.
25% of chlorine atoms have a mass number of 37.
What is the relative atomic mass of chlorine?

Answer 27

35.5