Topic 2-Bonding, Structure and the Properties of matter

Question 1

what is an ion

Answer 1

a charged particle that has gained or lost electrons to become stable

Question 2

why do we not really see group 3,4.5 ions

Answer 2

as it requires a lot more energy for them to lose or gain electrons

Question 3

how do ionic bonds form in terms of electron transfer

Answer 3

electrons are transferred making both atoms stable ions.the 2 ions have opposite charges and are attracted by electrostatic forces(ionic bond) which form an ionic compound

Question 4

what does an electrostatic force do

Answer 4

-they attract protons and electrons within ions and atoms
-they attract oppositely charged ions

Question 5

what does ionic bonding normally involve

Answer 5

a metal atom transferring 1 or more electron to a non metal atom to form 2 oppositely charged ions which are attracted to each other by electrostatic forces forming an ionic bond.this is called an ionic compound

Question 6

what do ionic compounds involve

Answer 6

each electron being attracted to those oppositely charged ions around them forming a 3d regular lattice structure

Question 7

list properties of ionic compounds

Answer 7

can conduct electricity-when aq or melted
have high melting and boiling points-ions are free to move about(charged particles)

Question 8

what are the formulas for hydroxide and sulfate ions

Answer 8

oh- and so4 2-

Question 9

why are brackets used-

Answer 9

to show that a ion like hydroxide needs 2

Question 10

list common ionic compounds and their symbols

Answer 10

nitrate-no- 3
carbonate- co 2- 3
ammonium ion nh+ 4

Question 11

what are displayed formulas downsides

Answer 11

they save time to draw complicated big models
dont show you anything about 3d shape of molecule

Question 12

what are the substances covalent bonds can make

Answer 12

small molecular substances-with strong covalent bonds but weak imf-eg water/methane

-polymers-used to make plastic bags/t-shirts
also giant covalent structures like silicon dioxide/diamond or graphite

Question 12

what are the properties of giant covalent structures

Answer 12

high melting and boiling points
apart from graphite cant conduct electrity

Question 12

what is the main difference between simple molecular substances and giant

Answer 12

Covalent substances that only contain a few atoms are called
simple molecular substances.

On the other hand, covalent substances with millions of atoms are called giant covalent structures.

Question 12

why are most simple molecules gases at room temp

Answer 12

In simple molecular substances, the individual molecules are held together by intermolecular forces that exist between the molecules.
These intermolecular forces are weak and so don’t require very much energy to break.
This means that they can be broken at relatively low temperatures. As a result most simple molecular substances exist in the gaseous state at room temperature.

Question 13

why do halogens exist at different states at room temp

Answer 13

Chlorine is a gas at room temperature.
Bromine is a liquid at room temperature.
Iodine is a solid at room temperature and gives off purple fumes.
The reason they are in different states at room temperature is that they have different melting and boiling points. As you go down group 7, the atoms (and thus molecules) get bigger. This means there will be more intermolecular forces, and so more energy (and a higher temperature) will be required to break them.

Question 14

what is a similarity between giant and simple molecular substances

Answer 14

they both cant conduct electricity

Question 15

4 facts on giant covalent structures

Answer 15

Every atom is connected by strong covalent bonds
No weak intermolecular forces as there is only one structure
High melting and boiling points
Cannot conduct electricity (except graphite)

Question 16

what are nano particles

Answer 16

tiny particles between 1-100nm long

Question 17

what are the uses of nano particles

Answer 17

medecine
catalysts
electronics
deodrants

Question 18

what is the difference in simple and giant molecular substances

Answer 18

giant have millions of atoms while simple have only a few

Question 19

4 point summary on giant molecular structures

Answer 19

Every atom is connected by strong covalent bonds
No weak intermolecular forces as there is only one structure
High melting and boiling points
Cannot conduct electricity (except graphite

Question 20

what are allotropes

Answer 20

different structural forms of the same element in the same physical state

Question 21

how many carbon atoms are bonded in diamond

Answer 21

4

Question 22

why can graphite conduct electric/heat

Answer 22

has 1 spare electron which becomes delocalised being able to conduct electricity and heat

Question 23

how is graphite arranged

Answer 23

atoms are arranged into hexagons which together form large flat sheets which are placed on top of each other to form many layers

Question 24

why is graphite slippery/soft

Answer 24

layers are free to slide over each other as there are no covalent bonds between them There are only weak imf holding them together requiring less energy to break

Question 25

Why is grapheme useful in electronics

Answer 25

Each atom donates an electron to a delocalised pool of electrons and therefore it can conduct electricity

Question 26

What are tubes and spheres of graphite called

Answer 26

Fullerenes

Question 27

What are the uses of fullerenes

Answer 27

Spheres Drug delivery Industrial catalysts Nanotubes In nanotechnology Electronics Tennis racket frames

Question 28

When happens between outer shell electrons and positive atoms of a metal

Answer 28

They become positive ions as they lose the outer shell electrons which become delocalised allowing the metal to conduct electricity

Question 29

How is a metal held together in a regular structure

Answer 29

The electrostatic forces of attraction between its positive ions and negative electrons hold it together

Question 30

Wgat are some qualities of metals

Answer 30

Can conduct electricity and heat Have high mp and bp Malleable

Question 31

What is an alloy

Answer 31

2 or more different elements

Question 32

How can some alloys be much stronger than pure metals

Answer 32

The atoms of the elements used can be different sizes disrupting the regular arrangement of atoms so the layers can no longer slide

Question 33

What is the diameter range of nano particles

Answer 33

1nm-100nm

Question 34

What are the key features/uses of nano particles

Answer 34

Have High sa to vol ratio Used as catalysts Used in nano medicine Silver nano particles have anti microbial properties so are used in surgical masks Used in electrical circuits

Question 35

What are risks using nano particles

Answer 35

New so long term effects pn our body are unknown Eg in Suncream where their high sa to vol ratio makes them more effective and have more skin coverage but may get into our skin and cells causing harm In oceans they may be damaging environment as we don’t know what happens when they get in the sea