Atomic Structure

Question 1

What did daltons theory say about the structure of an atom

Answer 1

1. All elements are made up of small invisible particles called atoms
2. Atoms cannot be created or destroyed
3. Atoms of different elements have different properties
4. When atoms combine they form molecules or compounds

Question 2

What did J.J. Thompson model of an atom look like

Answer 2

Plum pudding

Question 3

Who discovered the electron

Answer 3

J J Thompson

Question 4

Relative mass of proton

Answer 4

1

Question 5

Relative mass of neutron

Answer 5

1

Question 6

Relative mass of electron

Answer 6

1/1840

Question 7

Relative charge of proton

Answer 7

+1

Question 8

Relative charge of neutron

Answer 8

0

Question 9

Relative charge of electron

Answer 9

-1

Question 10

How to remember the relative charges

Answer 10

Neutrons= neutral
Protons= positive
Electrons= negative

Question 11

Where are the protons and neutrons

Answer 11

Nucleus

Question 12

Where are the electrons

Answer 12

In shells orbiting the nucleus

The shells can be filled by 2,8,8,8

Question 13

What is an atom composed of

Answer 13

An atom is composed of a small dense positively charged nucleus at the centre composed of protons and neutrons (most of the mass) with negatively charged electrons in shells orbiting the nucleus.

Question 14

Radius of an atom

Answer 14

0.1nm

Question 15

What’s the atomic number

Answer 15

The number of protons in the nucleus of an atom

Question 16

What’s the mass number

Answer 16

Total number of protons and neutrons in the nucleus of an atom

Question 17

How do the atoms of one element differ to the atoms of another

Answer 17

The n.o. of protons, neutrons and electrons found in each atom are different

Question 18

What is an element

Answer 18

A substance that consists of only one type of atom and it cannot be broken down into anything simpler by chemical means.

Question 19

What’s the top number

Answer 19

Mass number

Question 20

What’s the bottom number

Answer 20

Atomic number

Question 21

How to find number of neutrons

Answer 21

Mass - atomic number

(Top - bottom)

Question 22

The number of protons is equal to

Answer 22

The atomic number
Also the number of electrons

Question 23

Where do the electrons go first

Answer 23

In the shell closest to the nucleus first.
Each shell must be filled with its full quota before starting to fill the next.
First has 2
The rest have 8

Question 24

Ions

Answer 24

Atoms with electric charges

Question 25

Cations

Answer 25

Atoms with positive charges (loss of electron/s)

Question 26

Anions

Answer 26

Atoms with negative charges (gain of electron/s)

Question 27

Difference between cation and anion

Answer 27

Cation = positive ion
Anion = negative ion

Question 28

What makes something stable

Answer 28

Filled outer shells. Noble gases have full outer shells making them very stable.

Question 29

How can you make something more stable

Answer 29

Adding or losing an electron/s.
When they gain/lose electrons they form ions

Question 30

What would it mean if it said Ca 2+

Answer 30

Calcium has lost 2 electrons in its outer shell

Question 31

What would it mean if it said Na +

Answer 31

Sodium has lost one electron

Question 32

What would it mean if it said Cl -

Answer 32

Chlorine has gained one electron and became a chloride ion

Question 33

What are isotopes

Answer 33

Isotopes are atoms which have the same number of protons (so they are atoms of the same element) but they have a different number of neutrons (so they have a different mass number)

Question 34

This isn’t a question just an example
This is an example of a common isotope of chlorine

Answer 34

Chlorine 35 p=17 e=17 n=18. Chlorine 37 p=17 e=17 n=20

Question 35

What are the most common mass numbers of chlorine

Also how do you find the relative mass

Answer 35

75% of chlorine atoms have a mass of 35.

25% of chlorine atoms have a mass of 25.

This is to calculate the relative mass of chlorine from the mass number and abundances if it’s isotopes: Average mass number = (75x35)(25x37) divide by 100
= 35.5

Question 36

Calculate the relative atomic mass of boron when it contains…

19.77% 10B , 80.23% 11B

Answer 36

Method: (19.77x10)(80.23x11) divide by 100

=10.8

Question 37

Calculate the relative atomic mass of silicon when it contains ….

92.18% 28Si, 4.70% 29Si, 3.12% 30Si

Answer 37

Method: (92.18x28)(4.70x29)(3.12x30) divide by 100

=28.1

Question 38

How do you identify isotopes

Answer 38

The protons and electrons of different atoms are the same but they have a different number of electrons

Question 39

How to identify which elements are isotopes for each other

Answer 39

The bottom (atomic) number will be the same but the top (mass) number will be different

Question 40

How is the periodic table arranged

Answer 40

In order of atomic numbers

Question 41

Fill in this sentence…
For every element _________ number is unique

Answer 41

For every element atomic number is unique

Question 42

How many electrons can the first shell hold

Answer 42

2

Question 43

How many electrons does helium have

Answer 43

2

Question 44

As we go across the rows in the periodic table what happens to the second electron shell?

Answer 44

The outer shells gain an extra electron

Question 45

What particle in the atom did Chadwick discover

Answer 45

Neutron

Question 46

What did JJThompson do

Answer 46

Plum pudding model, stated negative electrons embedded in a positive sphere

Question 47

What did Rutherford do?

Answer 47

Model had negative electrons orbiting a positive nucleus