Chemical Bonding

Question 1

what is chemical bonding?

Answer 1

attraction between atoms involving electron transfer/sharing to form new compounds

Question 2

what is a grouped ion?

Answer 2

more than one atom involved in the ion

Question 3

what is the symbol for carbonate and its charge?

Answer 3

symbol = CO3

charge = 2-

Question 4

what is the symbol for ammonium and its charge?

Answer 4

symbol = NH4

charge = 1+

Question 5

what is the symbol and charge for hydroxide?

Answer 5

symbol = OH

charge = 1-

Question 6

what is the symbol and charge for nitrate?

Answer 6

symbol = NO₃

charge = 1-

Question 7

what is the symbol and charge for sulfate?

Answer 7

symbol = SO₄

charge = 2-

Question 8

what is the symbol and charge for phosphate?

Answer 8

symbol = PO₄

charge = 3-

Question 9

what is valency?

Answer 9

the number of electrons an atom needs to complete the outer shell

those electrons are either gained or lost

Question 10

do non-metals gain or lose electrons?

Answer 10

gain

Question 11

what is an ion

Answer 11

a charged particle (positive or negative)

Question 12

how does the cross rule work?

Answer 12

Question 13

are metals negatively or positively charged and why?

Answer 13

positively charged (cations)

they lose electrons

Question 14

are non-metals negatively or positively charged and why?

Answer 14

negatibely charged (anions)

they gain electrons

Question 15

in the centre of the atom are two sub-atomic particles

these particles are the …… and the …..

the ….. are positively charges

the ……have no charge and are …..

Answer 15

in the centre of the atom are two sub-atomic particles

these particles are the protons and the neutrons

the protons are positively charged

the **neutrons **have no charge and are neutral

Question 16

the centre of an atom is ….. charged

Answer 16

the centre of an atom is positively charged

Question 17

around the centre of the atom are negatively charges sub-atomic particles called …..

Answer 17

around the centre of the atom are negatively charges sub-atomic particles called electrons

Question 18

the overall charge on an atom is ….

the number of …… and …… are equal

Answer 18

the overall charge on an atom is zero

the number of **protons and electrons **are equal

Question 19

electrons are arranged in energy …. around the centre of the atom

the first energy …. is nearest to the centre and can take a maximum of …. electrons

the second and thur energy …. can take a maximum if …. electrons each

Answer 19

electrons are arranged in energy **shells **around the centre of the atom

the first energy shell is nearest to the centre and can take a maximum of 2 electrons

the second and thur energy shells can take a maximum if 8 electrons each

Question 20

when atoms bond with other atoms, the number of electrons in their outermost energy shell ……

Answer 20

when atoms bond with other atoms, the number of electrons in their outermost energy shell changes

Question 21

what are elements

Answer 21

substances that can’t be split into anything more simply by chemical means

Question 22

what do all atoms in elements share?

Answer 22

the same atomic number

Question 23

how are elements recognised in diagram?

Answer 23

the atoms have the same size or colour

Question 24

what are compounds?

Answer 24

a combination of two or more elements in fixed proportions, joined together by strong bonds

Question 25

does it matter if the compound is molecular, giant covalent or giant ionic?

Answer 25

no

Question 26

what is a mixture?

Answer 26

the various components can be in any proportions

Question 27

is an alloy a mixture? why?

Answer 27

yes because of the totally variable proportions

Question 28

what is the differences in proportions between mixtures and compounds

Answer 28

A compounds proportions never vary In a mixture the portions vary If you wanted to mix some silvery zinc metal with some yellow sulphur, you could use any proportions in zinc sulphide the proportions of zinc and sulphur have to be the exact same

Question 29

what is the differences in properties between mixtures and compounds

Answer 29

in elements, each element has its own properties, but the properties of the compound are different a mixture of hydrogen and oxygen would explode when you put it in a flame a compound of hydrogen and oxygen to make water would put out a flame

Question 30

what is the differences in ease of separation between mixtures and compounds

Answer 30

mixture can be separated by physical means e.g. change in temperature, or dissolving part of the mixture in a solvent like water, things that do not involve chemical reactions compounds have to be separated by chemical reactions e.g. electrolysis

Question 31

what is the differences in energy change between mixtures and compounds

Answer 31

there is little to no energy changes when making a mixture there is greater energy changes when making a compound

Question 32

explain why hydrogen is gas at room temperature

Answer 32

hydrogen is a simple molecule and so has weak intermolecular forces between its molecules these weak forces break at room temperature

Question 33

hydrogen chloride has a ...... molecular structure there are .... forces between the .... because of this, hydrogen chloride has a ..... boiling point

Answer 33

hydrogen chloride has a **simple** molecular structure there are **weak** forces between the **molecules** because of this, hydrogen chloride has a **low** boiling point

Question 34

why is pure copper malleable?

Answer 34

pure metals are malleable because of their same sized atoms and arrangement layers can easily slide over each other because in metals there are delocalised electrons which allow copper ions to do this

Question 35

bronze is a mixture of tin and copper, the tin atoms are much bigger than the copper atoms why is bronze not as malleable as copper

Answer 35

the different size of atoms (tin is much bigger than copper) mean that they can't slide over each other

Question 36

why do metals conduct electricity?

Answer 36

delocalised electrons fall between the layer of atoms and conduct electricity

Question 37

a substance has: melting point = 54⁰C boiling point = 120⁰C electrical conductivity as solid = poor electrical conductivity as liquid = poor electrical conductivity as aqueos solution = poor what type of structure is it?

Answer 37

covalent: simple

Question 38

a substance has: melting point = 403⁰C boiling point = 567⁰C electrical conductivity as solid = good electrical conductivity as liquid = good electrical conductivity as aqueos solution = not soluble what type of structure is it?

Answer 38

metallic

Question 39

a substance has: melting point = -210⁰C boiling point = -196⁰C electrical conductivity as solid = poor electrical conductivity as liquid = poor electrical conductivity as aqueos solution = poor what type of structure is it?

Answer 39

covalent: simple CHECK

Question 40

a substance has: melting point = 1610⁰C boiling point = 2230⁰C electrical conductivity as solid = poor electrical conductivity as liquid = poor electrical conductivity as aqueos solution = not soluble what type of structure is it?

Answer 40

covalent: giant

Question 41

a substance has: melting point = 615⁰C boiling point = 876⁰C electrical conductivity as solid = poor electrical conductivity as liquid = good electrical conductivity as aqueos solution = good what type of structure is it?

Answer 41

ionic

Question 42

a substance has: melting point = 3727⁰C boiling point = 4827⁰C electrical conductivity as solid = good electrical conductivity as liquid = good electrical conductivity as aqueos solution = not soluble what type of structure is it?

Answer 42

metallic

Question 43

a substance has: melting point = 56⁰C boiling point = 342⁰C electrical conductivity as solid = good electrical conductivity as liquid = good electrical conductivity as aqueos solution = good what type of structure is it?

Answer 43

metallic

Question 44

a substance has: melting point = 934⁰C boiling point = 1568⁰C electrical conductivity as solid = poor electrical conductivity as liquid = good electrical conductivity as aqueos solution = insoluble what type of structure is it?

Answer 44

ionic

Question 45

a substance has: melting point = -105⁰C boiling point = -45⁰C electrical conductivity as solid = poor electrical conductivity as liquid = poor electrical conductivity as aqueos solution = good what type of structure is it?

Answer 45

covalent: simple CHECK

Question 46

state whether you would expect calcium flouride (ionic bonding) to have a high or low melting point and why

Answer 46

high stronger attraction between the positive Cl atoms and negative F atoms lots of energy needed

Question 47

what is the chemical formula for Calcium Flouride

Answer 47

CaF₂

Question 48

what is the chemical formula for Potassium Bromide

Answer 48

KBr

Question 49

what is the chemical formula for Barium NItrate

Answer 49

Ba(NO₃)₂

Question 50

what is the chemical formula for Beryllium Oxide

Answer 50

BeO

Question 51

what is the chemical formula for magnesium phosphate

Answer 51

Mg₃(PO₄)₂

Question 52

what does the '(II)' in Copper (II) indicate?

Answer 52

each copper atom contributes 2 electrons

Question 53

why can copper conduct electricity?

Answer 53

because it has a sea of delocalised electronsnbetween the layers in the structure which are free to move

Question 54

why can copper be drawn into wires

Answer 54

copper is ductile the sea of delocalise delectrons mean the layers can slide easily over each other and be drawn into wires

Question 55

what is a use for poly(ethene)

Answer 55

wax in polish

Question 56

why does propanone and water (both simple molecular structures) have low boiling points

Answer 56

the attractive forces between their molecules are weak these require little energy to be overcome

Question 57

ammonia is: ionic bonding / covalent bonding insoluble in water / soluble in water

Answer 57

covalent bonding soluble in water

Question 58

methane is: ionic bonding / covalent bonding insoluble in water / soluble in water

Answer 58

covalent bonding insoluble in water

Question 59

poly(ethene) is: ionic bonding / covalent bonding insoluble in water / soluble in water

Answer 59

covalent bonding insoluble in water

Question 60

sodium chloride is: ionic bonding / covalent bonding insoluble in water / soluble in water

Answer 60

check

Question 61

sodium hydroxide is: ionic bonding / covalent bonding insoluble in water / soluble in water

Answer 61

ionic bonding soluble in water

Question 62

give two observations made during the reaction between magnesium and oxygen

Answer 62

a huge bright light is seen a sizzle is heard whilst the reaction occurs

Question 63

why is the melting point of magnesium oxide much higher than that of sodium chloride?

Answer 63

lattice is held together by stronger attraction this is because the ions have a higher charge and therefore a higher attraction

Question 64

Suggest and explain why silica is used to make bricks for high-temperature furnaces. In your answer, you should refer to the structure of, and bonding im, silica

Answer 64

giant covalent stucture strong covalent bonds between atoms lots of energy to breka bonds - makes them suitable to withdstand heat

Question 65

When glue sets it forms a giant covalent structure explain why the giant covalent structures have high melting points?

Answer 65

they have strong covalent bonds which take a lot of energy to break so it needs to be a high heat to break these bonds