EL5 The Molecules Of Life

Question 1

How do some light elements achieve stability?

Answer 1

By reaching the helium configuration of two outer shell electrons.

Question 2

How do elements achieve eight outer shell electrons?

Answer 2

By losing or gaining electrons.

Question 3

Why don’t non-metallic elements form ions?

Answer 3

It’s not energetically favourable.

Question 4

What is covalent bonding?

Answer 4

The sharing of electrons.

Question 5

What elements covalently bond?

Answer 5

Non metals.

Question 6

What does a dot and cross diagram show in covalent bonding?

Answer 6

How sharing electrons gives the atoms more stable electron structures.

Question 7

What are bonding pairs?

Answer 7

Electron pairs that form bonds.

Question 8

What are lone pairs?

Answer 8

Pairs of electrons that are not involved in bonding.

Question 9

What is a double bond?

Answer 9

Where two pairs of electrons form a covalent bond.

Question 10

What is a triple bond?

Answer 10

Where three pairs of electrons form a covalent bond.

Question 11

What are dot and cross diagrams useful for representing?

Answer 11

Individual electrons in a chemical bond.

Question 12

What can we also use to represent bonds?

Answer 12

Lines.

Question 13

What is a dative bond?

Answer 13

A covalent bond where both electrons come from the same atom.

Question 14

How is dative bonding shown?

Answer 14

By an arrow pointing away from the atom that donates the electrons.

Question 15

What is strong within simple covalent molecules?

Answer 15

The covalent intramolecular bonds.

Question 16

What are weak within simple covalent molecules?

Answer 16

The electrostatic attractions.

Question 17

What do the weak electrostatic attractions mean?

Answer 17

Small amounts of energy are needed to separate one molecule from another.

Question 18

What do elements and compounds with a simple molecular structure have?

Answer 18

Low melting and boiling points.

Question 19

What do simple covalent molecules not do?

Answer 19

Conduct electricity.

Question 20

What makes a covalent molecules shape?

Answer 20

Electron pair repulsion.

Question 21

How do groups of electrons arrange themselves?

Answer 21

As far apart as possible.

Question 22

Why do groups of electrons arrange themselves as far apart as possible?

Answer 22

Because similar charges repel.

Question 23

What bond angle is a tetrahedral shape?

Answer 23

109.5

Question 24

What molecules have a tetrahedral shape?

Answer 24

All carbon atoms that are surrounded by four single bonds.

Question 25

What groups of electrons repel the strongest?

Answer 25

Lone pairs of electrons.

Question 26

What is the bond angle for a pyramidal shape?

Answer 26

107

Question 27

What is the bond angle for a bent shape?

Answer 27

104.5

Question 28

What is a tetrahedral shaped molecule example?

Answer 28

Methane.

Question 29

What is a pyramidal shaped molecule example?

Answer 29

Ammonia.

Question 30

What is a bent shaped molecule example?

Answer 30

Water.

Question 31

How many groups of electrons are there in linear shaped molecules?

Answer 31

2

Question 32

What is the bond angle for a linear shaped molecule?

Answer 32

180

Question 33

How many groups of electrons are there in a planar shaped molecule?

Answer 33

3

Question 34

What is the bond angle for a planar shaped molecule?

Answer 34

120

Question 35

How many groups of electrons are there in a trigonal bipyramidal shaped molecule?

Answer 35

5

Question 36

What are the bond angles in a trigonometry bipyramidal shaped molecule?

Answer 36

90 and 120.

Question 37

How many groups of electrons are there in a octahedral shaped molecule?

Answer 37

6

Question 38

What is the bond angle in an octahedral shaped molecule?

Answer 38

90