Bonding

Question 1

When 2 different ______ join together, you get a compound.

Answer 1

elements

Question 2

______ bonding is when ions are held together by electrostatic attraction

Answer 2

ionic

Question 3

________ attraction holds positive and negative ions together - it is very strong

Answer 3

electrostatic

Question 4

The overall charge of any compound is ________

Answer 4

zero

Question 5

Magnesium chloride contains Mg2+ and Cl- ions

What would the balanced formula be for this

Answer 5

MgCl2

Question 6

Sodium chloride is an example of a _____ _____ _______ structure

Answer 6

giant ionic lattice

Question 7

Ionic compounds conduct electricity when…

Answer 7

they are molten or dissolved as there are free electrons and ions are free to move

Question 8

Ionic compounds have _____ melting points

Answer 8

high because they are held together by strong electrostatic forces which needs a lot of energy to overcome.

Question 9

Ionic compounds tend to _______ in water

Answer 9

dissolve as water is polar and the charged parts pull ions away from the lattice causing it to dissolve.

Question 10

What type of bond holds molecules together?

Answer 10

strong covalent bonds

Question 11

What does a single covalent bond share?

Answer 11

a pair of electrons

Question 12

Covalent bonding happens between 2 _____________

Answer 12

non metals

Question 13

Carbon atoms can form what type of structure due to them forming 4 strong covalent bonds?

Answer 13

giant covalent structure

Question 14

How are the carbon atoms arranged in graphite?

Answer 14

sheets of flat hexagons covalently bonded with 3 bonds each. the fourth outer electron of each carbon atom is delocalised

Question 15

Give examples of the properties of graphite

Answer 15

• weak bonds between the layers so easily broken so sheets can slide over eachother
• delocalised electron carry a charge so graphite is an electrical conductor
• low density so can be used to make strong lightwewight equipment
• high melting point due to strong bonds

-insoluble in any solvent

Question 16

In diamond, each carbon atom is covalently bonded to ____ other carbon atoms and arrange themselves in a _________ shape

Answer 16

4

tetrahedral

Question 17

Give examples of the properties of diamond

Answer 17

• very high melting point
• hard
• good thermal conductor
• cant conduct electricity as all electrons are held in localised bonds
• wont dissolve in any solvent
• can be cut

Question 18

define dative covalent bond and what is it represented by

Answer 18

dative covalent bond is where both electrons come from one atom

represented by an arrow pointing away from the donor atom

Question 19

electron charge clouds repel each other, give order of repulsion from highest to lowest

Answer 19

lone to lone
lone to bonding
bonding to bonding

Question 20

how to work out how many electron pairs a shape has?

Answer 20

take the central atom
work out how many electrons in outer shell
add one to this number for every atom it is bonded to
divide by 2 to find number of electron pairs
compare electron pairs to number of bonds to find the number of lone pairs and bonding pairs

Question 21

shapes with 2 electron pairs

Answer 21

linear - no lp

Question 22

shapes with 3 electron pairs

Answer 22

trigonal planar - no lp

Question 23

shapes with 4 electron pairs

Answer 23

tetrahedral - no lp
trigonal pyramidal - 1 lp
v shaped - 2 lp

Question 24

shapes with 5 electron pairs

Answer 24

trigonal bipyramidal - no lp
seesaw - 1 lp
t shaped - 2 lp

Question 25

shapes with 6 electron pairs

Answer 25

octahedral - no lp square planar - 2 lp

Question 26

define electronegativity

Answer 26

an atoms ability to attract the electron pair in a covalent bond

Question 27

which element is most electronegative ?

Answer 27

fluorine

Question 28

in a covalent bond between two atoms of different electronegativities, the bonding electrons will be pulled toward the more electronegative atom. this makes the bond ____

Answer 28

polar

Question 29

In a polar bond, the difference in electronegativity between the two atoms causes a permanent _____

Answer 29

dipole

Question 30

Define dipole

Answer 30

a difference in charge between the two atoms caused by a shift in electron density in the bond

Question 31

What happens to a bond when electronegativity increases?

Answer 31

becomes more polar

Question 32

In a substance made up of molecules that have permanent dipoles, there will be weak ________________ _____ of attraction between + and - charges on neighbouring molecules

Answer 32

electrostatic forces

Question 33

Where are Van der Waals forces found?

Answer 33

between all atoms and molecules

Question 34

How are VDW created?

Answer 34

Electrons in charge clouds are moving really quickly. At any moment the electrons in an atom are more likely to be at one side - this would create a temporary dipole. The dipole can cause another temporary dipole in the neighbouring atom/ other direction. They are then attracted to each other.

Question 35

In a solid at room temperature, what forces are holding them together in a lattice?

Answer 35

Van der Waals

Question 36

What is the strongest type of intermolecular force?

Answer 36

Hydrogen bonding

Question 37

rule for hydrogen bonding?

Answer 37

H bonds with N, O, F

Question 38

Examples of molecules with hydrogen bonding

Answer 38

water and ammonia

Question 39

properties of substances with hydrogen bonding

Answer 39

higher bp and mp more energy needed to break bonds

Question 40

why is ice less dene than liquid water?

Answer 40

As liquid water cools to form ice, the molecules make more H bonds and arrange into a regular lattice structure. In this, the H2O molecules are further apart on average than molecules in liquid water so ice is less dense.

Question 41

Metals exist as giant metallic lattice structures and have a _________ ______ 'sea'

Answer 41

delocalised electron

Question 42

describe metallic bonding

Answer 42

The + metal ions are attracted to the delocalised - electrons. They form a lattice of closely packed positive ions in a sea of delocalised electrons.

Question 43

properties of metals

Answer 43

high mp due to electrostatic attraction the more there are, the stronger the bonding so higher mp good thermal conductors as the delocalised electrons can pass kinetic energy to eachother good electrical conductors because the delocalised electrons can move and carry a charge metals are insoluble because the strength of the metallic bonds

Question 44

What do you need to overcome to melt or boil a simple covalent compound?

Answer 44

intermolecular forces you dont need to break the much stronger covalent bonds that hold the atoms together - this is why simple covalent compounds have relatively low mp and bp

Question 45

A substance will only conduct electricity if it contains ______ particles that are ____ to move.

Answer 45

charged free

Question 46

As water is a polar solvent, what type of particles dissolve well?

Answer 46

polar or charged