Bonding, Structure and Properties Flashcards
(26 cards)
PMT
Explain why alloys are harder than pure metals. [3]
Because there is a mixture of different elements which makes a distorted layer and makes it harder for the elements to slide.
over each other. [1]
Mistake: Didntn’t compare the two metals .
Compare the two metals. By using adjectives like “less” .
Didn’t know the difference between an atom and element.
Modal Answer:
(in an alloy) the atoms are of different sizes
(so) the layers (of atoms in an alloy) are distorted
(so in an alloy) the layers slide over each other less easily (than in a
pure metal
A student wants to compare the reactivity of an unknown metal, Q, with that
of zinc.
Both metals are more reactive than silver.
The student is provided with:
* silver nitrate solution
* metal Q powder
* zinc powder
* a thermometer
* normal laboratory equipment.
No other chemicals are available.
Describe a method the student could use to compare the reactivity of metal
Q with that of zinc.
Your method should give valid results.
Mistake: Knowledge gap
measure the temperature before
and after the reaction
when each metal is added to silver nitrate solution
same concentration / volume of solution.
the greater the temperature change the more reactive
Glass is made by heating sand with two other materials.
Which two other materials are used to make glass?
Tick (✓) two boxes.
Clay
Graphite
Limestone
Sodium carbonate
Sodium hydroxide. [2]
Limestone and sodium carbonate. [2]
Chlorine gas is used to produce poly(chloroethene).
Describe a test to identify chlorine gas.
Give the result of the test.
Test _______________________________________________________
___________________________________________________________
Result _____________________________________
(2)
Mistake: Misunderstanding.
The squeaky pop test is used to test for hydrogen gas.
(add damp) litmus paper
(litmus paper) is bleached
or
(litmus paper) turns white
Wood can be used instead of polymers to make window frames.
* Polymers are unreactive.
* Polymers are produced from crude oil.
* Wood breaks down in wet conditions.
* Wood is produced from trees.
Suggest one advantage of using polymers and one advantage of using
wood to make window frames.
Advantage of
polymers ________________________________________________
___________________________________________________________
Advantage of
wood _______________________
Polymers
break down slowly
(wood)
renewable
What is the definition of an alloy?.[1]
An alloy is the mixture of metals with other elements.
Ionic Bonding
Sodium oxide is a compound formed from the sodium and the non-metal oxygen.
Describe what happens when a sodium atom reacts with an oxygen atom.[4]
Two sodium atom each transfer one electrons in their outer shell becoming postively charged. [1]
The oxygen atom recieve the two electrons becoming negatively charged.[1]
The sodium and oxygen atom both have a noble structure [1]
They form an ionic bond forming magnesium oxide. [1]
Ionic Bonding
State the advanatge and disadvanatge of a dot and cross diagram .[2]
Advantage:
They show how ionic compounds are formed.
Disadvanatge:
They don’t show the structure of the atom.
Ionic Compounds
How can dissolved ionic compounds conduct electricity?[2]
Because the ions seperate and are free to move in the solution so they will carry electrical charge. [2]
Covalent Bonding
State the advanatge and disadvanatge of a displayed formula.[2]
Advanatage:
It shows how atoms are connected in large molecules.[1]
Diadvantage:
Doesn’t show the structure of a 3D structure.[1]
Covalent Bonding
State the advantage and disadvanatge of a 3D model.[2]
Advantage:
The atoms, the covalent bond and their arrangement in space next to each other.
Disadvantage:
They don’t show where the electrons in the bonds have come from.
Simple Molecular Substances
Explain the reason as why simple molecular substance have a low melting and boiling point.[2]
Because they have feeble intermolecular forces which means the molecules are easily parted from each other.[2]
Simple Molecular substances.
Why can’t simple molecular substance can’t conduct electricity?[2]
Because they aren’t charged and there is no free electrons or ions. [2]
Polymers
What is the definition of a polymer?[1]
lots of small units that are linked together to form a long molecule that has a repeating sections.[1]
Polymers
Why are polymers solids at room temperature and simple molecular substances are liquid and gases?[2]
Because the polymer molecules are larger than simple covalent molecules so more energy is needed to break them.[2]
Allotropes of Carbon
Explain the reason why diamonds are so hard?[1]
Because they form four covalent bonds.
Alltropes of Carbon
What is the definition of fullerenes?
They are hollow balls made from carbon
Allotropes of Carbon
How can the fullerene structure allow drugs to be delivered to the body?[1]
The fullerene structure forms around another molecule which is then trapped inside. [1]
Allotropes of Carbon
Describe the structure that helps fullernes to become great industrial catalysts?[1]
Their large surface area to volume ratio
Allotropes of Carbon
State 3 properties of nanotubes.[3]
The ratio between the length and the diameter of the nanotubes is very high.[1]
They can conduct electricity and thermal energy.[1]
They also have a high tensile strength.[1]
Nanoparticles
How can nanotube help deliver drugs right into the cells when they are needed.[1]
They are more absorbed more easily by the body.[1]
Nanoparticles
Why are silver nanoparticles be used to make surgical masks and wound dressing?[1]
because they have antibacterial properties.[1]
Nanoparticles
What is the disadvanatge of using nanoparticles.[1]
They can be washed away damaging the enviroment. [1]
What shape is a Buckminsterfullerene molecule?[1]
Spherical[1]
