Period 3 elements

Question 1

When sodium reacts, how many electrons does it lose?

Answer 1

1

Question 2

What ion is formed when sodium reacts?

Answer 2

Na+

Question 3

When magnesium reacts, how many electrons does it lose?

Answer 3

2

Question 4

What ion is formed when magnesium reacts?

Answer 4

Mg2+

Question 5

Why is sodium more reactive than magnesium?

Answer 5

It takes less energy to lose one electron as it does 2

Question 6

How does sodium react with cold water?

Answer 6

Vigourously

Question 7

What is formed when sodium reacts with water?

Answer 7

Molten ball on the surface, fizzing and H₂ gas

Question 8

What is the equation for the reaction of sodium with cold water?

Answer 8

2Na(s) + 2H₂O(l) -> 2NaOH(aq) + H₂(g)

Question 9

What is the pH of the solution formed when sodium reacts with water?

Answer 9

12-14

Strongly alkaline

Question 10

How does magnesium react with cold water?

Answer 10

Very slowly

Question 11

What is the pH of the solution formed when magnesium reacts with water?

Answer 11

9-10

Weakly alkaline

Question 12

Why is the solution formed from the reaction of magnesium and water only weakly alkaline?

Answer 12

Magnesium hydroxide is not very soluble in water, so relatively few hydroxide ions are produced

Question 13

What is the equation for the reaction of magnesium with cold water?

Answer 13

Mg(s) + 2H₂O(l) -> Mg(OH)₂ (aq) + H₂(g)

Question 14

Why does magnesium react faster with steam than cold water?

Answer 14

There is more energy

Question 15

What is the equation for the reaction of magnesium with steam?

Answer 15

Mg(s) + H2O(g) -> MgO(s) + H2(g)

Question 16

What do period 3 elements form when they react with oxygen?

Answer 16

Oxides in their highest oxidation state (usually)

Question 17

What is a period 3 elements highest oxidation state?

Answer 17

The same as their group numbers

Question 18

What is the exception to period 3 elements forming oxides with oxidation states the same as their group number?

Answer 18

Sulfur

Forms SO₂ - oxidation state of 4

Question 19

What is the equation for the reaction of sodium and oxygen?

Answer 19

2Na(s) + 1/2O₂ -> Na₂O(s)

Question 20

What is the equation for the reaction of magnesium with oxygen?

Answer 20

Mg(s) + 1/2O₂ -> MgO(s)

Question 21

What is the equation for the reaction of aluminium with oxygen?

Answer 21

2Al(s) + 1.5O₂ -> Al₂O₃(s)

Question 22

What is the equation for the reaction of silicon and oxygen?

Answer 22

Si(s) + O₂(g) -> SiO₂(s)

Question 23

What is the reaction of phosphorus with oxygen?

Answer 23

P₄(s) + 5O₂(g) -> P₄O₁₀(s)

Question 24

What is the equation for the reaction of sulfur with oxygen?

Answer 24

S(s) + O₂(g) -> SO₂(g)

Question 25

What is the reaction of Na in air like?

Answer 25

Vigorous

Question 26

What colour is the flame when Na is burnt?

Answer 26

Yellow

Question 27

What is the reaction of Mg in air like?

Answer 27

vigorous

Question 28

What colour is the flame when Mg is burnt?

Answer 28

Brilliant white

Question 29

What is the reaction of Al in air like?

Answer 29

Slow

Question 30

What colour is the flame when Al is burnt?

Answer 30

N/A

Question 31

What is the reaction of Si in air like?

Answer 31

Slow

Question 32

What colour is the flame when Si is burnt?

Answer 32

N/A

Question 33

What is the reaction of P in air like?

Answer 33

Spontaneously combusts

Question 34

What colour is the flame when P is burnt?

Answer 34

Brilliant white

Question 35

What is the reaction of S in air like?

Answer 35

Burns steadily

Question 36

What colour is the flame when S is burnt?

Answer 36

Blue