🧪 | Unit 9 | Periodic Table

Question 1

What are Group 7 elements called?

Answer 1

Halogens

Question 2

Name the halogens?

Answer 2

Flourine, Chlorine, Bromine, Iodine, Astatine

Question 3

Characteristics of halogens

Answer 3

• non-metals
• poisonous in elemental form
• have 7 valence electrons
• form anions with -1 charge
• m.p., b.p. and density increases down the group
• reactivity decreases down the group

Question 4

At room temperature, what state of matter is F?

Answer 4

Gas

Question 5

At room temperature, what state of matter is Cl?

Answer 5

Gas

Question 6

At room temperature, what state of matter is Br?

Answer 6

Liquid

Question 7

At room temperature, what state of matter is I?

Answer 7

Solid

Question 8

At room temperature, what state of matter is At?

Answer 8

Solid

Question 9

Colour of F?

Answer 9

Yellow

Question 10

Colour of Cl?

Answer 10

Pale-green

Question 11

Colour of Br?

Answer 11

Reddish-brown

Question 12

Colour of I?

Answer 12

Grey solid, sublimes into a purple vapour

Question 13

Colour of At?

Answer 13

Black, radioactive solid

Question 14

What is the trend in the reactivity of halogens as you go down the group?

Answer 14

The reactivity decreases as you go down the group.

Question 15

What colour are alkali metals when they are freshly cut?

Answer 15

Shiny, silvery surfaces when they are freshly cut.

Question 16

What is the density of alkali metals?

Answer 16

They have low densities

Question 17

What is the m.p. of alkali metals?

Answer 17

They have low m.p.

Question 18

Which Group is diatomic?

Answer 18

Group VII

Question 19

What is a halogen displacement reaction?

Answer 19

It’s when a more reactive halogen displaces a less reactive halogen in an aqueous solution of its halide.

Question 20

What are Group 1 elements called?

Answer 20

Alkali metals

Question 21

Characteristics of alkali metals

Answer 21

• soft metals
• have shiny, silvery surfaces when freshly cut
• form alkaline solutions with high pH values when reacting with water
• low m.p. and low density
• density increases as you go down the group
• m.p. decreases as you go down the group
• conduct heat and electricity

Question 22

What is the trend in the reactivity of alkali metals as you go down the group?

Answer 22

The reactivity increases as you go down the group.

Question 23

Observations: Li reacting with water

Answer 23

• fizzing (bubbles of H₂ produced)
• floats and moves around on the surface of the water
• dissolves into the water to produce an alkaline solution

Question 24

Observations: Na reacting with water

Answer 24

• bubbles of H₂
• melts into a shiny ball that dashes around the surface
• floats on water
• orange flame
• white trail of sodium hydroxide produced, dissolves in water and forms alkaline solution

Question 25

Why does Na/K melt when reacting with water?

Answer 25

Because alkali metals have low melting points and the reaction generates a lot of heat.

Question 26

How can the Na/K float on water, when reacting with water?

Answer 26

Because it is less dense than water

Question 27

How does the shiny ball of Na/K dash around the surface, when Na/K reacts with water?

Answer 27

The hydrogen produced in the reaction causes the ball to move around.

Question 28

Observations: Potassium reacting with water

Answer 28

- reacts more violently than Na - bubbles of H₂ gas - melts into a shiny ball that dashes around the surface - enough heat produced so hydrogen burns with a lilac flame

Question 29

Properties of transition metals

Answer 29

- very high m.p. - very high density - hard, strong metals - form coloured compounds - more than 1 oxidation state

Question 30

In Periodic Tables, where can you find the mass number of an element?

Answer 30

At the top of the element symbol.

Question 31

In Periodic Tables, where can you find the atomic number of an element?

Answer 31

At the bottom of the element symbol.

Question 32

What does the group number tell us?

Answer 32

How many valence electrons an element has can be seen with the group number.

Question 33

What does the period number tell us?

Answer 33

The period number tells us how many electron shells an atom has.

Question 34

Elements in the same group have similar properties. Why?

Answer 34

The number of valence electrons of elements in the same group are the same.

Question 35

Where can metals be found on the Periodic Table?

Answer 35

On the left

Question 36

Where can non-metals be found on the Periodic Table?

Answer 36

On the right

Question 37

What are the types of isotopes called?

Answer 37

Radioactive isotopes and non-radioactive isotopes.

Question 38

Use of radioactive isotopes?

Answer 38

- being able to find the date an object dates back to | - treating cancer in radiotherapy