Bonding, Structure, and Properties of matter

Question 1

What are the particles in ionic bonding?

Answer 1

The particles are positely charged ions.

Question 2

What are the particles in covalent bonding?

Answer 2

The particles are atoms which share pairs of electrons.

Question 3

What are the particles in metalic bonding?

Answer 3

The particles are atoms which share delocalised electrons.

Question 4

Where does ionic bonding occur?

Answer 4

In compounds formed from metals combined with non-metals.

Question 5

Where does covalent bonding occur?

Answer 5

In most non-metallic elements and in compounds of non-metals

Question 6

Where does metallic bonding occur?

Answer 6

In metallic elements and alloys.

Question 7

Explain the process of ionic bonding.

Answer 7

When a metal atom reacts with a non-metal atom electrons in the
outer shell of the metal atom are transferred. Metal atoms lose
electrons to become positively charged ions. Non-metal atoms gain electrons to become negatively charged ions. The ions produced by metals in Groups 1 and 2 and by non-metals in Groups 6 and 7 have the electronic structure of a noble gas (Group 0).

Question 8

What is an ionic compound?

Answer 8

A giant ionic lattice structure. Strong electrostatic forces of attraction between oppositely chaarged ions, in all directions of the lattice.

Question 9

Properties of an ionic compound.

Answer 9

High melting points and hgh boiling points due to the strong bonds. It takes a lot of energy to overcome this attraction. They can’t conduct electricity when they are solid as the ions are held in place but when molten or in aqeous solution they can as the ions cn carry a charge.

Question 10

What is a covalent bond?

Answer 10

When atoms share pairs of electrons, they form covalent bonds. The positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces.These bonds between atoms are strong.

Question 11

Properties of simple molecular substances.

Answer 11

> The atoms within the molecules are held together by very strong covalent bonds.
Intermolecular forces are very weak
The melting and boiling points are very low as energy only needs to break up the weak intramolecular forces.
As molecules get bigger, the strength of the intermolecular forces increases, so more energy is needed to break them, and the melting and boiling points increase.

Question 12

What are polymers?

Answer 12

Small units called monomers that repeat to form a long molecule.

Question 13

Intermolecular forces melting boiling properties.

Answer 13

Intermolecular forces between polymer moldecules are larger than between simple covalent molecules, so more energy is needed to break them. However, intermolecular forces are still weaker than ionic or covalent bonds.

Question 14

List giant covalent structures.

Answer 14

Diamond, graphite, silicon dioxide

Question 15

Properties of giant covalent structure.

Answer 15

High melting points and boiling points to break the covalent bonds.

Question 16

What are diamond bonds like?

Answer 16

Each carbon atom forms four covalent bonds in a very rigid giant covalent structure.

Question 17

What are graphite bonds like?

Answer 17

Each carbon atoms forms three covalent bonds to create layers of hexagons. Each carbon atom also has one delocalised electron.

Question 18

What are silicon dioxide bonds like?

Answer 18

\Sometimes called silica, this is what sand is made of. Each grain of sand is one giant structure of silicon and oxygen.

Question 19

What is diamond like?

Answer 19

Diamond is hard because it forms four covalent bonds. Strong covalent bonds take a lot of energy to break and gives diamond a high melting point. It does not conduct electricity has no free electrons or ions.

Question 20

What is graphite like?

Answer 20

> Each carbon atom only forms 3 covalent bonds, creates sheets of carbon atoms arranged in hexagons.
No covalent bonds between the layers - they’re held together weakly, so theyre free to move each other. This makes graphite soft and slippery, so it’s ideal as a lubricating material.
Has one delocalised electron that is free to move so each.

Question 21

Explain graphene.

Answer 21

Graphene is a sheet of carbon atoms joined together in hexagons. This sheet is just one atom thick, making it two-dimensional substance. The covalent bonds make it very strong but also incredibly light. It can also conduct electricity

Question 22

What are fullerenes?

Answer 22

Fullerenes are molecules of carbon, shaped like closed tubes or hollow balls. Mainly arranged in hexagons and sometimes pentagons or heptagons. Fullerenes can be used to ‘cage’ other molecules. The fullerene structure forms around another atom or molecule.

Question 23

What can fullerenes be used for?

Answer 23

This can be used to deliver a drug into the body. Have a huge surface area, so they could help make great industrial catalysts. Great lubricants.

Question 24

What are nanotubes?

Answer 24

Small carbon cylinders formed by fullerenes. The L:D is very high. Nanotubes can conduct both electricity and thermal energy, high tensile strength.

Question 25

What can nanotubes be used for?

Answer 25

Electronics, strengthen materials without adding weight such as tennis racket frames.

Question 26

What is the buckminster fullerene?

Answer 26

The first fullerene to be discovered. Molecular form C60 and forms a hollow sphere.

Question 27

What are metal - structure?

Answer 27

Metals consist of giant structures of atoms arranged in a regular
pattern.

Question 28

Explain metallic bonding.

Answer 28

Metals form giant structures in which electrons in the outer shells of the metal atoms are free to move. The metallic bond is the force of attraction between these free-moving (delocalised) electrons and positive metal
ions.

Question 29

How does melting/boiling point changbe in metals?

Answer 29

The greater the number of outer electrons that the metal has, the higher its melting/boiling point. This is due to the increased positive charge on the metal ion and the increased number of electrons that are delocalised, resulting in stronger bonding.

Question 30

Why do we need alloys?

Answer 30

Many pure metals are too soft for many uses. They can be made harder by adding another element to the pure metal, so forming an alloy. This explains why an alloy often has more uses than the pure elements it is made from.

Pure iron, for example, is very soft. Adding a small amount of tungsten to iron makes tool steel, which is harder than pure iron.
Steels are examples of alloys. There are many types of steel.

Question 31

Why are alloys are hard?

Answer 31

Different elements have different sized atoms. So, the netal atoms distort the layers of metal atoms, making it more difficult for them to slide over each other.

Question 32

What are alloys?

Answer 32

A mixture of two or more metals.

Question 33

What is the solid state of matter like?

Answer 33

> strong forces of attraction between each particle
holds them close together in fixed positions to form a regular lattice structure.
The particles don’t move from their positions, so all solids keep a definite shape and volume
The particles vibrate about their positions - the hotter the solid becomes the more they vibrate - expands slightly when heated.

Question 34

What is the liquid state of matter like?

Answer 34

In liquids, there’s a weak force of attraction between the particles. They’re randomly arranged and free to move over each other but tend to stick closely together.
Liquids have a definite volume but not a definite shape.
The particles are constantly moving with random motion. The hotter the liquid gets the faster they move - expands slightly when heated.

Question 35

What is the gas state of matter like?

Answer 35

In gases, forces of attraction between particles are very weak- theyre free to move and are far apart. The particles in gases travel in straightlines in any direction. Gases don’t keep a definite shape and volume and fills any container. They move constantly with random moition. The hotterr the gas gets, the faster they move. Gases expand slightly or increase in pressure as the heat does.

Question 36

What are the limitations of particle theory?

Answer 36

Paricles are not solid or inelastic or spheres. They are atoms, ions, or molecules. The model does not show the force between the particles, so there’s no way of knowing how strong they are.

Question 37

What is nanoscience?

Answer 37

Nanoscience refers to structures that are 1–100 nm in size, of the
order of a few hundred atoms

Question 38

What are fine particles?

Answer 38

Fine particles (PM2.5) have diameters between 100 and 2500 nm (1 x 10-7 m and 2.5 x 10-6 m).

Question 39

What are coarse particles?

Answer 39

Coarse particles (PM10) have
diameters between 1 x 10-5 m and 2.5 x 10-6 m. Coarse particles
are often referred to as dust.

Question 40

Nanoparticles in correlation to sa:v ratio.

Answer 40

Nanoparticles may have properties different from those for the same materials in bulk because of their high surface area to volume ratio. It may also mean that smaller quantities are needed
to be effective than for materials with normal particle sizes.

Question 41

Why can nanoparticles be used for tiny electric circuits for computer chips?

Answer 41

They conduct electricity.

Question 42

Silver nanoparticles have antibacterial properties what can it be used for?

Answer 42

Polymer fibres in surgical masks, wound dressings and deodorants.

Question 43

What are nanoparticles sedd for in cosmetics?

Answer 43

Improving moisturisers to make them less oily.

Question 44

Effects of nanoparticles on health:

Answer 44

> The way they affect the body isn’t fully understood, so it’s importat any new products are tested thoroughly to minimise risks.
Some people are worried that products including nanoparticles have been made available before the effects on human health have been investigated properly. We don’t know the long term health impacts.
As the long term impacts are not known, products containing nanoscale technology should be clearly labelled, so consumers can choose whether or not they want to use them.

Question 45

Why are nanoparticles being used in sun creams?

Answer 45

They have been shown to be better at protecting skin fro harmful UV rays. They give a better coverage tha traditional sun creams. However it’s not clear whether they can get into your body and damage cells. Or, be washed away and damage the environment.