Periodic Table

Question 1

What is the block of metals not under any group called?

Answer 1

Transition elements

Question 2

What are metalloids?

Answer 2

Elements located next to the staircase line, they have properties of both metals and non-metals.

Question 3

Name the nature of oxides across the groups in the periodic table

Answer 3

I, II: basic
III: amphoteric
IV, V, VI, VII: acidic
0: nil

Question 4

Explain what happens to atom size moving down a group.

Answer 4

The size of the atom increases going down a group, and valence electrons of an element will be further away from the attractive force of the nucleus. This allows the element further down a group to lose its valence electrons more easily.

Question 5

Elements of the same group have…

Answer 5

similar chemical properties.

Question 6

Name the properties of alkali metals (GRoup I)

Answer 6

are soft and can be cut easily.
have low melting and boiling points.
have low densities. Li, Na, K float on water.

Question 7

What are the trends of alkali metals moving down the group?

Answer 7

Going down the group, the melting/boiling points of alkali metals decrease, while the densities of alkali metals generally increase. The reactivity of alkali metals increases.

Question 8

Why are alkali metals stored in oil?

Answer 8

Alkali metals are highly reactive metals, and are thus stored in oil to prevent reaction with air and water. This is because each alkali metal only has one valence electron to lose.

Question 9

What happens when alkali metals react with cold water?

Answer 9

They form an alkali and hydrogen. The reaction becomes more violent going down the group.

Question 10

Why are alkali metals powerful reducing agents?

Answer 10

They readily give away their valence electron.

Question 11

What do alkali metals form?

Answer 11

Ionic compounds

Question 12

What are the physical properties of Group VII elements (Halogens)?

Answer 12

form covalent, diatomic molecules
have low melting and boiling points.
At r.t., F and Cl are gases, Br liquid, and I solid.

Question 13

What are the trends of halogens moving down the group?

Answer 13

Going down the group, their melting/boiling points increase while colours become darker. Their reactivity decreases.

Question 14

Why are halogens reactive non-metals?

Answer 14

Halogens are reactive non-metals, because each halogen only needs to gain one more electron to achieve stable electronic configuration.

Question 15

Explain what a displacement reaction is.

Answer 15

Halogens undergo displacement reactions with halide solutions. (Halides include F, Cl, Br, I ions). A more reactive halogen displaces a less reactive halogen from its halide solution. Halogen + Halide solution → New halide solution + new halogen

Question 16

Why are halogens powerful oxidising agents?

Answer 16

Halogens are powerful oxidising agents as they readily gain electrons. The displacement reaction is a redox reaction.

Question 17

What are the five properties of noble gases?

Answer 17

are monoatomic
are colourless at room temp.
have low m.p. and b.p.
are insoluble in water
are unreactive

Question 18

Why are noble gases unreactive?

Answer 18

Noble gases are unreactive because they have a completely filled valence shell and therefore a stable electronic structure. They rarely react to form compounds since they do not lose/gain/share electrons.

Question 19

What are noble gases used for?

Answer 19

Noble gases are used to provide an inert atmosphere (e.g. balloons, bulbs, lights, vehicle headlamps, welding stainless steel)

Question 20

What are the properties of transition elements?

Answer 20

are found between Groups II and III
have high melting and boiling points.
have variable oxidation states
form coloured compounds
them and their compounds are good catalysts

Question 21

What processes can transition elements be involved in?

Answer 21

Transition elements act as catalysts in reactions such as formation of ammonia (Haber Process), manufacturing margarine from polyunsaturated compounds, and catalytic converter.