Atoms

Question 1

Average size of an atom

Answer 1

100 picometers

Question 2

Proton

Answer 2

Positive nucleon with mass of 1

Question 3

Neutron

Answer 3

Neutral nucleon with mass of 1.

Question 4

Electron

Answer 4

A negative subatomic particle situated on a shell of an atom with a relative mass of 1/2000

Question 5

Nucleon

Answer 5

Subatomic particles situated in the nucleus of an atom

Question 6

Mass number

Answer 6

Number of protons and neutrons

Question 7

Atomic number

Answer 7

Number of protons

Question 8

How many protons are there in comparison to electrons in a neutral atom?

Answer 8

The number of electrons always equal the number of protons in a neutral atom

Question 9

What happens if there’s an unequal number of electrons to protons?

Answer 9

The atom becomes charged and is an ion

Question 10

Isotope

Answer 10

Different atomic forms of the same element, which have the same proton number but a different number of neutrons. (Same proton number but different mass numbers).

Question 11

Molecule

Answer 11

A group of atoms

Question 12

Relative atomic mass

Answer 12

The weighted mean mass of an atom. (Rounded to nearest 0.5 in periodic tables)

Question 13

Relative abundance

Answer 13

How much there is of each isotope compared to the total amount of the element in the world. (Ratio, fraction or percentage).

Question 14

First atomic model theory

Answer 14

Dalton’s billiard ball (1800’s)

Question 15

What did Dalton’s billiard ball show?

Answer 15

All matter is made of atoms that can’t be broken down.
Different elements are different atoms.
Atoms are rearranged in chemical reactions.
Compounds are two or more atoms joined.

Question 16

What was the second atomic model?

Answer 16

JJ Thompson’s plum pudding (1900’s)

Question 17

What did the plum pudding model show?

Answer 17

That there was negative subatomic particles within the atom.

Question 18

What was the third atomic model?

Answer 18

Rutherford’s nuclear atom 1900’s

Question 19

What did Rutherford’s nuclear atom show?

Answer 19

That there was a nucleus within the atom.

Question 20

What was the fourth atomic model?

Answer 20

Bohr’s electron orbits

Question 21

What did Bohr’s model show?

Answer 21

That electrons had orbits.

That there were neutrons and free space within the atom.

Question 22

Who Carried out the gold foil experiment and when?

Answer 22

Geiger and Marsden (Rutherford’s assistants) in 1911

Question 23

What did the gold foil experiment compose of?

Answer 23

A vacuum with alpha radiation, a piece of gold foil and a detector

Question 24

Why was it a vacuum in Geiger and Marsden’s experiment?

Answer 24

So that air particles wouldn’t get in the way

Question 25

What happened during Geiger and Marsden’s experiment?

Answer 25

A beam of alpha particles was aimed at gold foil and their passage through was detected. Some atoms were reflected, deflected or would pass straight through. This supported Rutherford’s atomic model.

Question 26

What particles repel?

Answer 26

Positive and positive

Question 27

What did the gold foil experiment show?

Answer 27

There’s much free space in the atom.
The nucleus has a positive charge.
The nucleus is large.

Question 28

Which energy levels are filled first?

Answer 28

The lowest

2 8 8 2

Question 29

What happens when atoms have full electron shells?

Answer 29

They are more stable. They are also less reactive as they don’t need to gain/lose electrons.

Question 30

What happens when an atoms outer shell isn’t full?

Answer 30

It needs to react to maintain a stable, full outer shell.

Question 31

How do you work out an elements electronic configuration?

Answer 31

It’s atomic number

Question 32

What are electrons generally represented by on diagrams?

Answer 32

An X