Periodic Table

Question 1

John Newlands

Answer 1

Arranged elements by increasing atomic weight

Noticed every eighth element had similar properties and coincided with the triads- law of Octaves

Question 1

Dimitri Mendeleev

Answer 1

Refined Newlands ideas by using all known data for each element and arranging them into groups and periods

Periodic table established when a new element matched his prediction and filled a gap

Question 2

Johann Döbereiner

Answer 2

Arranged elements in a pattern
Linked properties and found some made triads and that atomic weight of triad’s second element was average of the other two

Question 3

Covalent bonding

Answer 3

Non metals combine by sharing electrons

Question 4

What properties have covalent bonds

Answer 4

Low melting points, weak bonds and weak intermolecular forces
Do not conduct electricity

SHARED ELECTRONS

Question 5

What kind of metals are in group one

Why do they have similar properties

Answer 5

Alkali metals

They all have one electron in outer shell

Question 6

Why are alkali metals stored under oil

Answer 6

They react with air and vigorously with water

Question 7

What colour does a lithium compound give when burned

Answer 7

Red

Question 8

What colour does a sodium compound give when burned

Answer 8

Yellow

Question 9

What colour does a potassium compound give when burned

Answer 9

Lilac

Question 10

What is produced when alkali metals react with water

Answer 10

A hydrogen and a hydroxide

Question 11

In group one are the metals more or less reactive the further down they are

Answer 11

More reactive

Question 12

In group one what happens to boiling and melting points of the alkali metals, the further down they are

Answer 12

They both decrease

Question 13

Why are the elements in group one more reactive the further down in the periodic table they are

Answer 13

Elements further down have outer shells further away from the nucleus making it easier for an atom to lose an electron from its shell

Question 14

Is oxidation loss or gain of electrons

Answer 14

Loss

Question 15

Is reduction loss or gain of electrons

Answer 15

Gain

Question 16

What are non-metals in group 7 known as

How many electrons in outer shell

Answer 16

Halogens

Seven electrons in outer shell

Question 17

Name first four halogens

Answer 17

Flourine
Chlorine
Bromine
Iodine

Question 18

What are the states of flourine, cholrine, bromine and iodine at room temeprature

Answer 18

Flourine is a gas
Chlorine is green gas
Bromine is an orange liquid
Iodine is a grey solid

Question 19

What are flourine, cholrine, bromine and iodine used for

Answer 19

Fluorine used in toothpaste
Chlorine sterilises water and makes pesticides and plastics
Iodine sterilises wounds

Question 20

What do halogens react with to make metal halides

Answer 20

Halogens react with alkali metals to form metal halides

Question 21

As we go down group 7 are the elements more or less reactive

Answer 21

Less reactive

Flourine is most reactive

Question 22

In a water solution of its metal halide, what will a halogen displace

Answer 22

A halogen displaces a less reactive halogen, solution forms

Eg. If chlorine is passed through aqueous potassium bromine solution
Bromine is formed due to displacement

Question 23

In group seven what happens to boiling points, melting points and density of the alkali metals, the further down they are

Answer 23

They increase

Question 24

Why is flourine the most reactive of the halogens

Answer 24

It is easiest for it to gain the extra electron as the outer shell is closer to the influence of the nucleus

Question 25

What metals are included in transition metals They have typical qualities

Answer 25

``` Iron Copper Platinum Mercury Chromium Zinc ```

Question 26

Compounds of transition metals are often coloured What colour are copper compounds

Answer 26

Blue

Question 27

Compounds of transition metals are often coloured What colour are iron(II) compounds

Answer 27

Grey/green

Question 28

Compounds of transition metals are often coloured What colour are iron (III) compounds

Answer 28

Orange-brown

Question 29

Transition metals and their compounds can be used as catalysts in chemical reactions What are two examples of this

Answer 29

Iron is used in haber process | Nickel is used in manufacture of margarine

Question 30

Thermal decomposition

Answer 30

Substance is broken down into simpler substances by heating

Question 31

When transition metals are heated under thermal decomposition what occurs

Answer 31

Colour change | Decompose to form a metal oxide and carbon dioxide

Question 32

When does limewater turn milky

Answer 32

When carbon dioxide us present

Question 33

What is the reaction between transition metal ions and sodium hydroxide solution called

Answer 33

A precipitation reaction

Question 34

In thermal decomposition of transition metal carbonates, | What are the products of copper carbonate (II)

Answer 34

Copper carbonate(II) = Copper(II) oxide + carbon dioxide

Question 35

In thermal decomposition of transition metal carbonates, | What are the products of iron carbonate (II)

Answer 35

Iron carbonate(II) = Iron(II) oxide + carbon dioxide

Question 36

What can metal compounds in solution form when sodium hudroxide solution is added to them

Answer 36

Precipitates (insoluble solids)

Question 37

Iron is a transition metal what are it's uses

Answer 37

Iron is used to make steel it is very strong Steel used for cars

Question 38

Copper is a transition metal what are it's uses

Answer 38

Copper is a good conductor Used for electrical wiring Used to make brass

Question 39

Give properties of metals

Answer 39

Lustrous eg. For jewellery Hard with high density eg. For drill bits High tensile strength to bear loads High melting and boiling points Good conductors of heat and electricity eg. saucepans and wiring

Question 40

How are metal atoms held together and how are they arranged As metal atoms pack together, what structure do they build

Answer 40

Metal atoms held together by metallic bond Packed closely in regular arrangement As metal atoms pack together they build a structure of crystals

Question 41

Why do metals have high melting and boiling points

Answer 41

Metal held together by strong electrostatic attraction between metal ions and delocalised electrons Lots of energy needed to overcome the strong metallic bonds

Question 42

Why do metal atoms form a metallic bonds when they are packed together

Answer 42

Atoms packed so close the outer electron shells overlap and form metallic bonds The overlap allows electron to be free (delocalised)

Question 43

How can the structure of metallic bonds be described

Answer 43

Closely packed metal ions in a sea of delocalised electrons

Question 44

In metal atoms, how are metals able to conduct electricity

Answer 44

The free movement of delocalised electrons allows metal to conduct electricity Atoms close together and electrons can move from atom to atom

Question 45

At low temperatures some metals can become superconductors Describe a superconductor

Answer 45

A superconductor has very little or no resistance to the flow of electricity

Question 46

Superconductors have low resistance, when is this useful

Answer 46

When you require: A powerful electromagnet eg. Inside medical scanners Very fast electronic circuits eg. Supercomputer Power transmission that does not lose energy

Question 47

Why are superconductors expensive to use

Answer 47

They operate at about -200'c which is costly and impractical We are trying to find one that will work at room temperature