Topic 1: Let's React

Question 1

Define Atoms

Answer 1

All of the materials around us are made up of tiny building block

Question 2

Define Element

Answer 2

When a substance is made up of one type of atom

Question 3

Proton: Location, Mass, Electrical Charge

Answer 3

nucleus, X1800, +1 charge

Question 4

Electron: Location, Mass, Electrical Charge

Answer 4

shell around the nuclues, X1800, no charge

Question 5

Neutron: Location, Mass, Electrical Charge

Answer 5

Shell around the nucleus, 1, -1 charge

Question 6

How to find no. of neutrons?

Answer 6

Mass number - atomic number

Question 7

Rule the maximum number of electrons each shell can hold.

Answer 7

2n^2, where n = the shell number

Question 8

Electronic Configuration

Answer 8

2,8,8,2

Question 9

What do the periods show on the periodic table?

Answer 9

The number of shells that contain electrons. It is numbered 1-7.

Question 10

What do the groups show on the periodic table?

Answer 10

The number of electrons in the outer (valence) shell. For groups 13-18, subtract 10.

Question 11

What does the atomic number of an element tell us?

Answer 11

The amount of electrons and protons in an element.

Question 12

What does the mass number of an element tell us?

Answer 12

How many protons + neutrons.

Question 13

What is the ground state

Answer 13

Electrons in the lowest energy shells

Question 14

What does heating an element cause it to do?

Answer 14

• causes an electron to absorb energy and jump to a higher energy level.
• the electron is excited and unstable and quickly returns to a lower energy level
• releases a fixed amount of energy in the form of coloured light!!
• visible light can be emitted when electrons return to a lower energy level

Question 15

What ion causes the flame colour to differ? Give evidence

Answer 15

It is the metal cation causing the flame colour as we tested compounds where different metal cations bonded with the same ion.

Question 16

List 3 limitations of flame tests

Answer 16

1. Different metals may produce similar flame colours
2. Most metal ions are not excited by the flame of a bunsen burner as it is not hot enough
3. Low accuracy and the tests are purely qualitative.

Question 17

Applications of flame tests

Answer 17

1. Fireworks
2. Electric Street Signs
3. Street Lights (Sodium Chloride)

Question 18

What is an excited state?

Answer 18

any energy state higher than the ground state. It is less stable and tends to return to the ground state by releasing energy in the form of light.

Question 19

What is a photon?

Answer 19

Coloured light energy

Question 20

What is an ion?

Answer 20

is an atom or a group of atoms that has an electrical charge, either positive or negative

Question 21

What is a cation?

Answer 21

An atom that loses electrons and therefore has more protons than electrons, having a positive overall charge

Question 22

What is an anion?

Answer 22

An atom that gains electrons, having more electrons than protons and so has a negative overall charge.

Question 23

Example of ion on calcium

Answer 23

Calcium (2,8,8,2) loses 2 electrons to from Ca^2+ (2,8,8) which is the same electronic configuration as Argon (2,8,8) which is Calciums nearest Noble gas.

Question 24

What determines how an atom behaves?

Answer 24

The number of electrons it has surrounding the nucleus.

Question 25

What is special about noble gases

Answer 25

They are the least reactive elements, already having full outer shells, therefore they don't need to lose or gain electrons.

Question 26

What happens to metal atoms to gain a full outer shell?

Answer 26

They lose electrons

Question 27

What happens to non-metal atoms to gain a full outer shell?

Answer 27

They gain electrons

Question 28

Law of Conservation of Mass

Answer 28

States that during a chemical reaction, matter cannot be created or destroyed. All the atoms present at the start of the reaction are present at the end.

Question 29

Characteristics of a chemical reaction

Answer 29

the chemical bonds holding the atoms together break and form new substabnces. Chemical change is difficult, if not impossible to reverse

Question 30

Examples of chemical change

Answer 30

Burning toast, cooking an egg, burning wood in fire are all examples of a chemical change.

Question 31

What does COBALT stand for?

Answer 31

C olour Change O dour Change B ubbles appear A ppearance or disappearance of a solid L ight or sound produced T emperature change

Question 32

What happens during a chemical reaction?

Answer 32

The bonds in the reactants are broken the atoms are re-arranged and new bonds form to make products.

Question 33

Reactants

Answer 33

Substance you have at the beginning

Question 34

Products

Answer 34

When the reaction is complete

Question 35

Why are symbols used in chemical reactions?

Answer 35

- to show the state of the reactants - to show the state of the products - reaction conditions

Question 36

(s)

Answer 36

solid

Question 37

(l)

Answer 37

liquid

Question 38

(g)

Answer 38

gas

Question 39

(aq)

Answer 39

aqueos

Question 41

Examples of slowing down reactions

Answer 41

fruit going brown, spoiling of food, rusting

Question 42

What is the collision theory?

Answer 42

The more collisions between particles ina. given time, the faster the reaction

Question 43

What does a collision need in order for it to be successful?

Answer 43

the molecules must collide with enough energy and the particles must have the correct orientation

Question 44

What happens if particles collide with lower energy?

Answer 44

If they collide with less energy than the minimum required, they will bounce off each other.

Question 45

The rate of measure is...

Answer 45

how fast the products are made or reactants are used up.

Question 46

What happens to rate of reaction overtime?

Answer 46

The concentration of reactants decreases, reducing the frequency of collisions between particles and so the reaction slows down.

Question 47

Why does increased temperature increase the rate of reaction?

Answer 47

The particles have more energy, meaning they are more faster and are more likely to collide with other particles. When the particles collide, they do so with more energy, and so the number of successful collisions increases.

Question 48

What happens to the rate of reaction in a cold mixture?

Answer 48

The particles move more slowly, collisions are less frequent and have less energy so there are fewer successful collisions.

Question 49

Why does increased concentration increase the rate of reaction?

Answer 49

- At a higher concentration there are more particles within a given volume. This means that the particles are more likely to collide and therefore more likely to react.

Question 50

Why does increased surface temperature increase the rate of reaction?

Answer 50

There is an increased area for the reactant particles to collide with. The smaller the pieces, the larger the surface area, meaning more collisions and a greater chance of reaction

Question 51

Why does the use of a catalyst increase rate of reaction?

Answer 51

It provides a surface for the chemical reaction to take place on and hence increases the frequency of collisions. It also provides a different pathway for the reaction with lower energy required.

Question 52

Why are catalysts so important for the industry?

Answer 52

1. Products can be made more quickly, saving time and money 2. Reduce the need for higher temperatures, saving fuel and reducing pollution 3. Are not used up in reactions, so they can be recovered chemically unchanged. This means they can be used again and again.