Module 2- Teachers

Question 1

What do chemists call the forces which hold atoms together?

Answer 1

Bonds

Question 2

What happens to outer electrons in a covalent bond?

Answer 2

There shared between two nuclei

Question 3

What the definition of a covalent bond

Answer 3

The electrostatic attraction if two positive nuclei for a shared pair of electrons

Question 4

What type of elements join together by covalent bonding?

Answer 4

Non-metal elements

Question 5

How many atoms make up a diatomic molecule?

Answer 5

Two atoms

Question 6

Name the 7 diatomic molecules?

Answer 6

Hydrogen, nitrogen, fluorine, oxygen, iodine, chlorine, bromine

Question 7

Name the two types of covalent compounds?

Answer 7

Covalent network
Covalent molecule

Question 8

State the definition of a molecule

Answer 8

A group of non-metal atoms joined together

Question 9

Is the nucleus of an atom positively or negatively charged?

Answer 9

It has a positive charge

Question 10

What charge do electrons have

Answer 10

Electrons are negatively charged

Question 11

Give the names (and charges) of the subatomic particles present in atoms.

Answer 11

protons (positive), neutrons (neutral) and electrons (negative)

Question 12

Why is an atom neutral ?

Answer 12

It is neutral because the number of protons (or positive charge on nucleus)
= number of electrons (or negative charges).

Question 13

State the location and charge on a proton, neutron and electron.

Answer 13

Proton - one positive (in nucleus)
Electron - one negative (outside nucleus)
Neutron - neutral (in nucleus)

Question 14

What is the atomic number of an atom?

Answer 14

The atomic number is the number of protons in the nucleus of an atom.

Question 15

What is meant by the mass number?

Answer 15

This is the number of protons + neutrons in the nucleus of an atom.

Question 16

Can you state what is meant by the term isotope ?

Answer 16

Same atomic number or number of protons
Different mass number or number of neutrons

Question 17

What is meant by relative atomic mass?

Answer 17

This is the average mass of an element taking into account the number and proportions of each isotope

Question 18

How are electrons arranged in an atom?

Answer 18

Electrons are arranged in energy levels. There are 2 electrons in the 1st energy level or 8 in the 2nd energy level

Question 19

How many protons, electrons and neutrons in 23Na ?

Answer 19

11 protons
11 electrons
12 neutrons

Question 20

What type of elements are conductors of electricity?

Answer 20

Metals elements and carbon

Question 21

Do covalent compounds conduct electricity?

Answer 21

No. The do not conduct electricity as there are no charged particles which are free to move.

Question 22

Why do atoms react together?

Answer 22

Atoms form bonds to reach a stale electron arrangement

Question 23

In which state do metals conduct

Answer 23

Solid, molten or dissolved in water

Question 24

What kind of bonding is present between non-metal atoms ?

Answer 24

Covalent bonding

Question 25

When do covalent compounds conduct electricity?

Answer 25

Never. They do not conduct electricity

Question 26

What kind of bonding is present between metals and non-metal elements when they combine?

Answer 26

Ionic bonding

Question 27

When do ionic compounds conduct electricity and why?

Answer 27

Ionic compound only conduct either in a molten state or when dissolved in water as
IONS CAN MOVE

Question 28

Why do covalent networks have very high melting points?

Answer 28

Covalent networks have very high melting points as lots of strong covalent bonds have to be broken which needs lots of energy

Question 29

Explain why covalent molecules have low melting points?

Answer 29

Covalent molecules have low melting points as there are weak forces of attraction between the molecules

Question 30

What is meant by electrolysis ?

Answer 30

The process of breaking up an ionic compound by means of electricity to form its element

Question 31

What is an ion?

Answer 31

It’s an atom that has lost or gained an electron

Question 32

What kind of compounds are liquids and gases at room temperature?

Answer 32

Covalent compounds

Question 33

During electrolysis what happens to each electrode?

Answer 33

In electrolysis of an ionic compound the positive metal ions move to the negative electrode. The negative non-metal ions move to the positive electrode.

Question 34

Definition of a metallic bond?

Answer 34

Metallic bonding is the electrostatic attraction between positively charges ions and delocalised electrons.

Question 35

Why does d.c. have to be used in electrolysis

Answer 35

A d.c. source is used to keep a constant positive and negative electrode and allow the products to be identified

Question 36

Definition of an ionic bond?

Answer 36

An ionic bond is the electrostatic attraction between positive and negative ions

Question 37

Why does ionic compounds only conduct when molten or in solution and not when solid?

Answer 37

The ions are free to move in a molten state. They are tightly held in a lattice and the ions cannot move in a solid

Question 38

How would you describe the melting point of ionic compounds

Answer 38

Ionic compounds have high melting points as it takes a lot of energy to break the strong ionic bonds and break up the ionic lattice.

Question 39

What type of structure do solid ionic compounds exist

Answer 39

They exist as a lattice of oppositely charged ions.

Question 40

Why do metals conducts?

Answer 40

They have delocalised electrons