Molecules

Question 1

What does an atom look like?

Answer 1

Question 2

What are the relative masses of protons, neutrons, and electrons?

Answer 2

protons - 1
neutrons - 1
electrons - 1/2000

Question 3

what are the charges of protons, neutrons and electrons?

Answer 3

protons - +1
neutrons - 0
electrons - -1

Question 4

How do you recognise the metals and non-metals from their position on the periodic table?

Answer 4

Question 5

What is the mass number?

Answer 5

It is the number of protons and neutrons added together in an atom.

Question 6

What is the atomic number?

Answer 6

the number of protons in an atom, which is equal to the number of electrons.

Question 7

How do you work out the relative atomic mass?

Answer 7

Use the formula:

Question 8

What is the relative atomic mass?

Answer 8

The relative atomic mass (A_r) of atoms is the average mass of all the different isotopes of an element.

Question 9

What are isotopes?

Answer 9

Atoms of the same element with different numbers of neutrons, but the same number of protons and electrons.

Question 10

How do you work out the number of electrons, protons and nuetrons from periodic table?

Answer 10

protons = 12
electrons = 12
neutrons = 24-12 =12

Question 11

What are the properties of metals?

Answer 11

• Solid at room temperature
• Malleable
• Conductive (heat)
• Conductive (electricity)
• Ductile
• Hard
• Shiny
• High melting/boiling point
• Sonorous

Question 12

What are the properties of non-metals?

Answer 12

• Dull
• Low melting points
• Poor conductors of electricity
• Poor conductors of heat
• Low density
• Brittle

Question 13

how does the electron configuration of an element relates to its position in the periodic table?

Answer 13

the group (column) shows the number of electrons in the atoms in the outer shell.
the period (row) shows the number of electron shells.

Question 14

Why don’t noble gases react with anything?

Answer 14

they already have full outer shells.

Question 15

what is an ion?

Answer 15

A charged particle formed when atoms lose/gain electrons .

Question 16

When are positive ions formed and what does this happen to?

Answer 16

when an atom loses electrons. This happens to metals.

Question 17

When are negative ions formed and what does this happen to?

Answer 17

when atoms gain electrons. This happens to non-metals.

Question 18

How do you predict the charges of atoms for when they turn into ions?

Answer 18

group 1 - +1
group 2 - +2
group 3 - +3

group 5 - -3
group 6 - -2
group 7 - -1

Question 19

What is the charge on the ion of silver?

Answer 19

+1

Question 20

What is the charge on the ion of copper?

Answer 20

can be +1 or +2, look for roman numerals

Question 21

What is the charge on the ion of iron(III)?

Answer 21

+3

Question 22

What is the charge on the ion of iron(II)?

Answer 22

+2

Question 23

What is the charge on the ion of zinc?

Answer 23

+2

Question 24

What is the charge on the ion of lead?

Answer 24

+2 or +4, indicated by roman numerals

Question 25

What is the formula and charge of hydrogen ion?

Answer 25

H⁺

Question 26

What is the formula and charge of hydroxide ion?

Answer 26

OH^-

Question 27

What is the formula and charge of ammonium ion?

Answer 27

NH₄⁺

Question 28

What is the formula and charge of carbonate ion?

Answer 28

CO₃^2-

Question 29

What is the formula and charge of nitrate ion?

Answer 29

NO₃^-

Question 30

What is the formula and charge of sulfate ion?

Answer 30

SO₄^2-

Question 31

how are ionic compounds structured?

Answer 31

ions are structured in a giant ionic lattice. The positive and negative ions strongly attract each other to make a regular lattice structure.

Question 32

How do you write ionic formulae for ionic compounds?

Answer 32

use the swap and drop method: eg NaCl Na1+ Cl1- Na1Cl1 NaCl

Question 33

Why do ionic compounds have high melting/boiling points?

Answer 33

Due to strong electrostatic forces between positive and negative ions, which takes lots of energy to overcome.

Question 34

Can ionic compounds conduct electricity when solid and why?

Answer 34

No, the ions are not free to move.

Question 35

Can ionic compounds conduct electricity when melted or dissolved in water and why?

Answer 35

Yes, ions are free to move.

Question 36

Can simple covalent molecules conduct electricity and why?

Answer 36

No, because there are no free charged particles to move.

Question 37

Are the melting/boiling points in simple covalent molecules low or high?

Answer 37

low, due to weak intermolecular forces.

Question 38

What is meant by giant covalent bonding?

Answer 38

consists of a large number of non-metal atoms joined by many covalent bonds (they are **not** molecules). lots of energy is needed to break the covalent bonds due to a very high melting point. they are arranged in a repeating pattern- giant lattice

Question 39

What are examples of giant covalent bonding?

Answer 39

diamond and graphite diamond - 4 bonds for Carbon atom graphite - 3 bonds for each Carbon atom. Consists of hexagonal layers.

Question 40

Why do giant covalnet substances have high melting points?

Answer 40

Because they are held together by strong covalent bonds. takes a lot of energy to break bonds and seperate carbon atoms.

Question 41

Why can graphite conduct heat and electricity but diamond cannot?

Answer 41

Diamond can't conduct because it has no free electrons. Graphite can conduct because it has 1 delocalised electron per atom, which can move along together between layers.

Question 42

How is buckministerfullerene structured?

Answer 42

It is a simple covalent substance which has 3 covalent bonds per carbon atom. It is shaped like a sphere

Question 43

What are the properties of buckministerfullerene?

Answer 43

It has a low melting/boiling point due to the weak forces between molecules which allow them to slide over each other. Don't conduct electricity because the free electrons it has can't move between molecules. It is soft due to weak bonds.

Question 44

Draw a labelled diagram to show metallic bonding

Answer 44

Question 45

Why do metals have high melting points?

Answer 45

due to strong electostatic forces of attracation between positive ions + delocalised electrons which require lots of energy to overcome

Question 46

Why can metals conduct heat and electricity?

Answer 46

They have delocalised electrons which can move

Question 47

Why do metals have high melting points?

Answer 47

They have strong electrostatic forces of attraction between the positive ions and delocalised electrons, which require lots of energy to overcome.

Question 48

Why are metals malleable?

Answer 48

The layers of metal ions can slide over each other.

Question 49

What is an alloy and why are they stronger than pure metals?

Answer 49

Alloys contain more than one of metal ion, these ions have different sizes which means the layers cannot slide over each other very easily. This means alloy are sronger than pure metals.