Periodic Table

Question 1

Metallic character on a period decreases_____________and increases_________

Answer 1

From left to right across a period

From right to left across a period

Question 2

Metallic character in a group increases____________and decreases_______

Answer 2

As up go down the group

As you go up the group

Question 3

All metallic elements

Answer 3

Have outer shells electrons 1-4

Question 4

Group 1 metals…

Answer 4

-Are soft
-Melting and boiling points decrease as you go down the group (they become more reactive as you go down the group)
They have LOW MELTING AND BOILING POINTS
-rate of reaction increases as you go down the group
-The density increases as you do down the group
-Gets softer as you go down the group
-Because of their extreme reactiveness they are stored in oil
(To prevent reaction with air )

Question 5

The periodic table is…

Answer 5

….a method of classifying elements that is used to predict properties of elements

Question 6

Lithium, sodium and potassium…

Answer 6

Are all group 1 metals, alkali metals. This is because when they react with water they produce alkaline solutions, metal hydroxide is formed when alkaline metals react with water.

Question 7

Chlorine, bromine and iodine…

Answer 7

Are all halogens in group 7

Question 8

Trends in Group 7 elements: Melting and boiling points

Answer 8

Melting point and boiling point
The halogens have low melting points and boiling points. This is a typical property of non-metals. The melting points and boiling points then increase as you go down the Group.

Question 9

Trends in Group 7 elements: colour

Answer 9

Colour
The halogens become darker as you go down the group. Fluorine is very pale yellow, chlorine is yellow-green and bromine is red-brown. Iodine crystals are shiny purple-black but easily turn into a dark purple vapour when they are warmed up.

Question 10

Trends in Group 7 elements: reactivity

Answer 10

Decrease as you go down the group fluorine is the most reactive.

F &Cl are gases
Br is a liquid
I & At are solids

Question 11

Why does the reactivity increase as you go down the group?

Answer 11

All alkali metals have one electron in the outer shell. In a reaction, this electron is lost and the alkali metal forms a +1 ion. As you go down group 1, the number of electron shells increases – lithium has two, sodium has three etc. Therefore, the outermost electron gets further from the nucleus. The attraction from the positive nucleus to the negative electron is less. This makes it easier to remove the electron and makes the atom more reactive.

Question 12

Reactions with metals

Answer 12

The halogens react with metals to make salts called metal halides.
metal + halogen → metal halide
For example, sodium reacts with chlorine to make sodium chloride (common salt).
sodium + chlorine → sodium chloride
2Na(s) + Cl2(g) → 2NaCl(s)
The reaction between sodium and a halogen becomes less vigorous as you move down Group 7. Fluorine reacts violently with sodium at room temperature. Chlorine reacts vigorously when in contact with hot sodium. Iodine reacts slowly with hot sodium.

Question 13

Halogens: conduct electricity?

Answer 13

Halogens are all poor conductors of heat and electricity – typical of non–metals.

Question 14

Trends of group 7 elements: density

Answer 14

The density of the halogens increases down Group 7 halogens.

Question 15

Note on naming halogen compounds:

Answer 15

When halogens combine with other elements in simple ionic compounds the name of the halogen element changes slightly from …ine to …ide.

Fluorine to fluoride etc.

Question 16

Reactions with other halides:

Answer 16

When you add Chlorine water to a solution of Potassium Bromide, the solution turns orange. This reaction is taking place:
Cl2 (aq) + 2KBr (aq) —-> 2KCl (aq) + Br2 (aq)
Chlorine + Potassium Bromide —> Potassium Chloride + Bromine

This is called displacement.

Bromine has been, what we called, Displaced for a more reactive halogen. It’s a bit like how girlfriends and boyfriends function nowadays. Girl A is with Boy A. The more attractive male, Boy B comes along and displaces Boy A.

Question 17

Displacement is when:

Answer 17

What this means is that when a halogen reacts with a salt such as Potassium Bromide (one that contains a -ide), the more reactive halogen will take the place of the less reactive halogen, as we clearly saw in the example just now. Chlorine is definitely more reactive than Bromine, as it is higher up in the Group and reactivity decreases down a group, so it displaces the Bromide in the salt to form Potassium Chloride.

Question 18

Transition metals:

Answer 18

• Have high densities
• High melting points
• Form coloured compounds
• Often act as catalysts in elements and compounds

Question 19

Noble gases (VIII)

Answer 19

• unreactive because they have full outer shells, so they are stable
• monoatomic gases, exists as one atom

Question 20

Uses of noble gases:

Answer 20

-argon is used in lamps
Used in light bulbs. The very thin metal filament inside the bulb would react with oxygen and burn away if the bulb were filled with air instead of argon. Argon stops the filament burning away because it is unreactive.

-helium is used to fill balloons and is used in airships.
Used in balloons and airships. It is much less dense than air, so balloons filled with it float upwards.

-Neon
Used in advertising signs, it glows when electricity is passed through it. Different coloured neon lights can be made by coating the inside of the glass tubing of the lights with other chemicals.

-Krypton
Used in lasers. Krypton lasers are used by surgeons to treat certain eye problems and to remove birthmarks.