Chem Chapter 3 (Chemical Bonding)

Question 1

Define elements

Answer 1

A substance that can not be further devided into smaller substances by chemical means

Question 2

Define metals

Answer 2

Metals are chemical elements or alloys that are shiny and have a high conductivity of heat and electricity

Question 3

Define non-metals

Answer 3

Non metals are chemical elements that are generally poor conductors of heat and electricity

Question 4

Define compounds

Answer 4

2 or more elements that have been chemically bound together in a fixed position

Question 5

Define mixtures

Answer 5

2 or more elements that are not chemically bound together in a fixed position

Question 6

The composition of mixtures

Answer 6

Variable composition

Question 7

The composition of compounds

Answer 7

Constant composition

Question 8

Define variable composition

Answer 8

A composition where the relative amounts of the elements can be changed

Question 9

Define constant composition

Answer 9

A composition where the elements have a set ration between them

Question 10

Are mixtures joined together

Answer 10

No

Question 11

Are compounds joined together

Answer 11

Yes

Question 12

Properties of elements in mixtures

Answer 12

They keep the properties of the substances involved

Question 13

Properties of elements in compounds

Answer 13

The properties are different from those of the elements it contains

Question 14

Can mixtures be sperated

Answer 14

Yes they can be separated

Question 15

Can compounds be separated

Answer 15

No compounds can not be separated but they can be obtained using chemical reactions

Question 16

What is covalent bonding

Answer 16

The binding of two non-metals together

Question 17

What is ionic bonding

Answer 17

The binding of a metal and a non-metal

Question 18

What is metallic bonding

Answer 18

The bonding of two metals

Question 19

What are the diatonic molecules

Answer 19

Hydrogen, Oxygen, nitrogen, fluorine, chlorine, bromine

Question 20

Physical properties of simple covalent compounds

Answer 20

1.They are held by weak intermolecular forces so they have low melting point .
2. One melted, molecules are free to move but have no charge and so the don’t conduct electricity

Question 21

Define ions

Answer 21

Ion is an atom or group of atoms with a positive or negative charge.

Question 22

How are ions formed

Answer 22

Ions are formed when an atom or groups of atoms gain or lose electrons

Question 23

Do metal atoms gain or lose electrons

Answer 23

Metal atoms loose electrons to form positive charges

Question 24

Do non-metal atoms gain or lose electrons

Answer 24

They gain electrons and form negative charges

Question 25

Why are positive and negative charge attracted to eachother

Answer 25

They are attracted because of electrostatic forces

Question 26

Define cations

Answer 26

Cations are positively charges ions

Question 27

What are anions

Answer 27

Anions are negatively charged ions

Question 28

Physical properties of ionic compounds

Answer 28

1. They have high melting and boiling points
2. Ions in water can move and hence can transfer electric current
3. Melted ionic compounds are able to conduct electricity as well, as ions can move

Question 29

What is the regular arrangement of ionic compounds

Answer 29

It is a lattice

Question 30

Are ionic compounds soluble in water

Answer 30

Ionic compounds are soluble in water as water is attracted to charged ions and so many ionic solids dissolve

Question 31

In what states to ionic compounds conduct electricity

Answer 31

When they are melted or dissolved in water. Not in solid

Question 32

Hardness of diamond

Answer 32

It is very durable due to its strong covalent bonds which extend all through out the crystal as each carbon is attached to 4 others-tetrahedrally

Question 33

Conductivity of diamond

Answer 33

Diamond does not conduct electricity as all it’s free electrons are used in making covalent bonds

Question 34

Uses of diamond for its hardness

Answer 34

It is used in drill bits, diamond saws and glass cutters

Question 35

Graphites hardness

Answer 35

1. It is soft
2. The layers can slide in eachother and has a slippery feel (used as lubricant)
3. Carbons arranged in 2D layer linked with hexagonal.
4. Each carbon atom is bonded with 3 others
5. The attraction force between the layers is weaker

Question 36

Graphite electrical conductivity

Answer 36

It conducts electricity as the free electrons are not used by the layered atoms

Question 37

Use of graphite for its hardness

Answer 37

Pencil and lubricant

Question 38

Use of graphite for its conductivity

Answer 38

As electrodes and for brushes in electric motor

Question 39

Why can metals conduct electricity

Answer 39

Cause the free moving electrons can carry the electric current with them

Question 40

Metallic bonding structure

Answer 40

Positive ions all lined up in lattice structure

Question 41

Physical properties of metallic compounds

Answer 41

1. High conduction of heat and electricity die to free moving electrons
2. High melting point and strong due to negatively charged electrons being attracted to positive nucleus
3. Malleable and ductile due to the present if free moving electrons between the positive nucleus that makes the structure able to slide in itself

Question 42

Which molecular bonding’s have ions

Answer 42

Ionic and Metalic

Question 43

The 4 Giant covalent structures

Answer 43

1. SIlicon
2. Silicon Dioxide
3. Carbon (Diamond)
4. Carbon (Graphite)

Question 44

Define allotrope?

Answer 44

When two or more forms of an element exist in the same physical state

Question 45

Examples of allotropes?

Answer 45

Diamond and graphite