C2 - The Periodic Table

Question 1

What is a compound?

Answer 1

Two or more elements which are chemically bonded.

Question 2

What is a mixture?

Answer 2

Two or more substances which are 𝗡𝗢𝗧 chemically bonded.

Question 3

List the methods of separating mixtures

Answer 3

Filtration, Evaporation, Distillation, Fractional distillation, Crystallisation, Chromatography. As these do not include chemical reactions and no new substances are made.

Question 4

List the names of scientists who helped develop the model of the atom (in chronological order)

Answer 4

John Dalton, J.J. Thomson, Ernest Rutherford, Niels Bohr, James Chadwick

Question 5

What did John Dalton do?

Answer 5

Developed the Solid Sphere Model: Atoms are indivisible, indestructible particles, each element having its own kind of atom.

Question 6

What did J.J Thomson do?

Answer 6

Proposed the Plum Pudding Model: Atoms are composed of negatively charged electrons embedded in a positively charged sphere.

Question 7

What did Ernest Rutherford do?

Answer 7

Developed the Nuclear Model: Discovered the nucleus, a dense positive center, with electrons orbiting around it.

Question 8

What did Niels Bohr do?

Answer 8

Proposed the Bohr Model: Electrons orbit the nucleus in fixed energy levels or shells.

Question 9

What did James Chadwick do?

Answer 9

Discovered the neutron, completing the understanding of the atomic nucleus as containing both protons and neutrons.

Question 10

What are columns and rows called in the periodic table?

Answer 10

Columns - Groups
Rows - Periods

Question 11

What are group 1 elements called?

Answer 11

Alkali metals

Question 12

What are group 2 elements called?

Answer 12

Alkali earth metals

Question 13

What are group 7 elements called?

Answer 13

Halogens

Question 14

What are group 8 elements called?

Answer 14

Noble gases

Question 15

list 4

physical properties of alkali metals

Answer 15

• low density
• low melting/boiling point
• soft
• shiny when cut

Question 16

list 2

chemical properties of alkali metals

Answer 16

• very reactive
• reactivity increases going down the group

Question 17

list 2

chemical properties of halogens

Answer 17

• very reactive
• reactivity decreases going down the group

Question 18

list 2

chemical properties of noble gases

Answer 18

• inert (unreactive)
• very low melting/boiling point

Question 19

What is observed when an alkali metal is reacted with water?

Answer 19

• effervescence (fizzes)
• floats on the surface
• moves around on the surface

Question 20

word equation:

alkali metal + water →

Answer 20

metal hydroxide + hydrogen

Question 21

What is the colour of each aqueous solution:
- Cl₂
- Br₂
- I₂

Answer 21

• Cl₂ - green
• Br₂ - orange
• I₂ - brown

Question 22

When potassium is reacted with water, what colour does it burn?

Answer 22

Lilac

Question 23

Why are alkali metals reactive?

Answer 23

They have 1 electron in their outer shell, meaning they can lose this electron easily.

Question 24

Why does reactivity increase going down the group with alkali metals?

Answer 24

The electrostatic force of attraction between the nucleus and outer shell becomes weaker as the element becomes larger, therefore losing the outer electron becomes easier.

Question 25

Why are halogens reactive?

Answer 25

They have 7 electrons in their outer shell, meaning they can gain an electron easily.

Question 26

Why does reactivity increase going down the group with halogens?

Answer 26

The electrostatic force of attraction between the nucleus and an attracted electron becomes weaker as the element becomes larger, therefore gaining an electron becomes harder.

Question 27

What are the elements in the middle of the periodic table called?

Answer 27

transition metals

Question 28

How did Mendeleev predict properties of undiscovered elements?

Answer 28

by looking at the properties of the elements next to the undiscovered one

Question 29

Why did Mendeleev swap some elements positions?

Answer 29

to line up elements with similar chemical properties

Question 30

chemical properties of transition metals

Answer 30

- they form coloured ions of different charges - less reactive than alkali metals

Question 31

# name the group of substances that are usually used for catalysts

Answer 31

transition metals

Question 32

# name: states of matter: - flourine - chlorine - bromine - iodine

Answer 32

- gas - gas - liquid - solid

Question 33

# chemical equation: K + H₂O →

Answer 33

2K + 2H₂O → 2KOH + H₂

Question 34

3 observations of the reaction sodium + chlorine

Answer 34

1. Yellow flame 2. White smoke 3. White solid formed