S1 - Atomic structure

Question 1

What do atoms consist of?

Answer 1

A central nucleus, composed of protons and neutrons, surrounded by electrons, orbiting in shells

Question 2

What makes the nucleus have a positive charge? Why is almost the whole mass of the atom concentrated in the nucleus?

Answer 2

The protons are heavy and positively charged

Question 3

Describe a neutron and electron

Answer 3

• Neutrons are heavy and have a neutral charge

- Protons are tiny and light and have a negative charge

Question 4

What is the relative mass and charge of protons, neutrons and electrons?

Answer 4

Proton - mass 1, charge +1
Neutron - mass 1, charge 0
Electron - mass 1/2000, charge -1

Question 5

What is the atomic number?

Answer 5

The number of protons

Question 6

Where does the mass number next to the symbol of the element?

Answer 6

Top left hand corner

Question 8

Where does the atomic number go next to the symbol of the element?

Answer 8

Bottom left hand corner

Question 9

What is the mass number?

Answer 9

The number of protons and neutrons

Question 11

How do you work out the number of neutrons?

Answer 11

Subtract the atomic number from the mass number

Question 12

Atoms of the same element all have what the same?

Answer 12

The number of protons

Question 13

Atoms of different elements will have different what?

Answer 13

Number of protons

Question 14

What is the relative atomic mass?

Answer 14

A measure of the mass of one atom of the element compared with the mass of an atom of C-12 (mass is exactly 12) - the average mass of all isotopes of an element

Question 15

What two things do you need to know to work out the relative atomic mass?

Answer 15

Relative mass of each isotope and its relative abundance

Question 16

What does the relative abundance mean?

Answer 16

How much there is of the each isotope compared to the total amount of the element in the world

Question 17

What is the equation for working out the relative atomic mass?

Answer 17

(% of isotope 1 × mass of isotope 1) + (% of isotope 2 × mass of isotope 2) ÷ 100

Question 18

What is an isotope?

Answer 18

Atoms that have the same number of protons and electrons but different number of neutrons

• same proton number
• different mass numbers

Question 19

Give an example of an isotope

Answer 19

C-12 and C-14 (used in carbon dating)

Question 20

What does the period table show?

Answer 20

Elements put in order of increasing atomic number

Question 21

How is the period table laid out?

Answer 21

Elements with similar properties are put in the same column (group)

Question 22

What group the elements are put into corresponds to what?

Answer 22

The number of electrons the elements have on their outer shell (group 1 have 1, group 2 have 2…) This is why there properties are similar

Question 23

What are the five electron shell rules?

Answer 23

1) Electrons always occupy shells (energy levels)
2) Lowest energy levels are always filled first - closest to the nucleus
3) Only a certain number of electrons are allowed in each shell
4) Atoms are happy when they have full electron shells - like the noble gases
5) In most atoms the outer shell is not full making the atom want to react

Question 24

What are the certain number of electrons allowed in each shell?

Answer 24

1st shell = 2
2nd shell = 8
3rd shell = 8 (still filling)

Question 25

What is the electronic configuration?

Answer 25

The distribution of electrons in an atom

Question 26

How do you work out the electronic configuration?

Answer 26

Use your period table and the electron shell rule (atomic number = protons and the no. of protons = no. of electrons)

Question 27

What are the electronic configurations of the first 20 elements?

Atomic numbers;
H - 1
He - 2
Li - 3
Be - 4
B - 5
C - 6
N - 7
O - 8
F - 9
Ne - 10
Na - 11
Mg - 12
Al - 13
Si - 14
P - 15
S - 16
Cl - 17
Ar - 18
K - 19
Ca - 20

Answer 27

H - 1
He - 2
Li - 2.1
Be - 2.2
B - 2.3
C - 2.4
N - 2.5
O - 2.6
F - 2.7
Ne - 2.8
Na - 2.8.1
Mg - 2.8.2
Al - 2.8.3
Si - 2.8.4
P - 2.8.5
S - 2.8.6
Cl - 2.8.7
Ar - 2.8.8
K - 2.8.8.1
Ca - 2.8.8.2

Question 28

What is the number of outer electrons in each of the following groups?

Group 1
Group 2
Group 3
Group 4
Group 5
Group 6
Group 7
Group 0

Answer 28

Group 1 - 1
Group 2 - 2 
Group 3 - 3
Group 4 - 4
Group 5 - 5
Group 6 - 6
Group 7 - 7
Group 0 - 0