Lets react

Question 1

Inside atoms

Answer 1

An atom consists of a heavy nucleus of protons and neutrons, surrounded by space containing moving electrons.
Protons, neutrons and electrons are called subatomic particles.

Question 2

Protons

Answer 2

located in the nucleus, the mass compared to 1x electron is x1800. the electric charge is +1

Question 3

Neautron

Answer 3

located in the nucleus. The mass compared to 1x electron is x1800. The electric charge is 0.

Question 4

Electron

Answer 4

located in the shells around the nucleus. The mass compared to 1x electron is 1. electric charge is -1

Question 5

Atoms are neutral

Answer 5

This means that the number of protons (+) is equal to the number of electrons (-).

Question 6

Atomic number

Answer 6

The number of protons an atom has.

Question 7

Mass number

Answer 7

The number of protons plus neutrons in the nucleus.

Question 8

Sub-atomic particles

Answer 8

The number of protons plus neutrons in the nucleus. Electrons orbit/move around the nucleus in regions of space called shells.

Question 9

Early Models of the Atom

Answer 9

Electrons are arranged in shells (energy levels). The levels closest to the nucleus are of less energy than those further away (think stability).

Question 10

Electron Levels (Shells)

Answer 10

The Low energy electrons are closest to the nucleus. The first shell (1) is lowest in energy, 2nd level next and so on

Question 11

Electron configuration

Answer 11

1st shell: 2 electrons maximum
2nd shell: 8 electrons maximum
3rd shell: 8 electrons maximum
4th shell: 2 electrons maximum

Question 12

Electron movement through shells

Answer 12

Electrons can sometimes move to a new energy level / shell. An electron absorbs energy to “jump” to a higher energy, less stable level. When an electron falls to a lower energy, more stable level, energy is emitted as coloured light.

Question 13

Flame Tests - purpose?

Answer 13

Provide evidence for the existence of energy levels .Used to identify a few metals.

Question 14

Flame test colours

Answer 14

lithium goes red, sodium goes orange and copper goes teal.

Question 15

Explain why the outer shell (valence shell) electrons are important

Answer 15

because it shows insight into the chemicals properties and determines its reactivity to form other chemical bonds.

Question 16

ion

Answer 16

An ion is an atom or group of atoms that has an electrical charge, either positive or negative.

Question 17

cation

Answer 17

is a positive ion that has lost and electron or more.

Question 18

anion

Answer 18

is a negative ion that has gained an electron or more.

Question 19

why do atoms form ions?

Answer 19

they make ions to create stability, which in tales a full outer shell.

Question 20

which elements form cations

Answer 20

metals loses electrons to create cations

Question 21

which elements form anions

Answer 21

non-metals gain electrons to create anions.

Question 22

how do bonds form between ions

Answer 22

The opposite charges on the ions cause the ions to bond, or be held together, by electrostatic forces.

Question 23

Law of Conservation of mass

Answer 23

The Law of conservation of mass states that matter can neither be created or destroyed.

Question 24

describe how to do an experiment to show the Law of conservation of mass

Answer 24

The total mass of the reactants equals the total mass of all the products.

Question 25

indications a chemical reaction has occured

Answer 25

change in colour, temp change, bubbles, a solid appears or disappears, and odour is produced, and a flame or light becomes present

Question 26

What are the reactants of a chemical reaction?

Answer 26

The reactants are the starting substances that undergo change during the reaction to form new products.

Question 27

What are the products of a chemical reaction?

Answer 27

The products are the substances that are formed as a result of the reaction between the reactants.

Question 28

What is a physical change?

Answer 28

Physical changes are changes affecting the form of a chemical substance, but not its chemical composition, and can be reversed

Question 29

What is a chemical change?

Answer 29

is a change of materials into another, new materials with different properties and one or more than one new substances are formed, and cannot be reversed

Question 30

Explain the meaning of ‘rate of a chemical reaction’?

Answer 30

The rate of a chemical reaction refers to the speed at which reactants are converted into products over a given period of time.

Question 31

List the factors that can increase the rate of a chemical reaction

Answer 31

Temperature
Surface area
Concentration of reactants
Use of a catalyst/enzyme

Question 32

How does temperature affect the rate of reaction?

Answer 32

As the temp is increased so is the rate of reaction, this is because at a higher temp the particles have more kinetic energy there for they are more likely to collide.

Question 33

How does an increased concentration affect the rate of reaction?

Answer 33

at a higher concentration, there are more particles in the same amount of space meaning the particles are more likely to collide.

Question 34

How does an surface area affect the rate of reaction?

Answer 34

As we increase the surface area, we increase the rate of reaction. If the solid is split into several pieces, the surface area increases. this means more area for the reactant to collide with.

Question 35

How does an enzyme/catalyst affect the rate of reaction?

Answer 35

catalyst are chemical that speeds up a chemical reaction. A catalyst provides a surface for the reaction to take place on and hence increases the frequency of collisions.

Question 36

Explain the function of a catalyst.

Answer 36

catalyst are chemical that speeds up a chemical reaction. The benefits are; Products can be made more quickly, saving time and money, they reduce the need for high temperatures, saving fuel and reducing pollution.