Science

Question 1

What is a unit

Answer 1

A physical quantity we can use when measuring
Some examples include force (N), moment (NM) and density (KG/m^3)

Question 2

What is an si unit

Answer 2

A quantity that is defined in terms of base or other derived quantities must then be a derived quantity.
They are all used in experiments

Question 3

List some examples of si units

Answer 3

Mass(KG), length (M), Time(s), Moles (mol), Current(A), temperature (K or c) and luminosity (cd)

Question 4

What is a scalar quantity

Answer 4

A quantity with magnitude only

Question 5

What is a vector quantity

Answer 5

A quantity with direction and mahnitude

Question 6

What are Cartesian coordinates

Answer 6

A coordinate relative to the fixed reference point( the origin)

Question 7

How does a fact differ from an opinion

Answer 7

A fact can be proven but an opinion is debatable

Question 8

What is science

Answer 8

The use of evidence to construct testable explanations and predictions

Question 9

What are the six steps of a scientific method

Answer 9

1.observation
2.question
3.hypothesis
4.experiment
5.conclusion
6.result

Question 10

What did John dalton discover

Answer 10

1803 - All matter is made of atoms
“Atoms cannot be broken into anything smaller”

Question 11

What did JJ Thompson discover

Answer 11

1897 - the electron and the plum pudding model

Question 12

What did earnest Rutherford discover

Answer 12

1910 - the alpha scattering experiment showed:
1) the model was mostly empty space ( most passed through
2)the nucleus was positively charged (some slightly deflected)
3) most mass in the middle (a few bounce back)

Question 13

What did Neil’s Bohr discover

Answer 13

He theorised that the electrons orbit at set distances with specific amounts of energy and that they can switch energy levels by absorbing or emitting electro-magnetic radiation

Question 14

What did James Chadwick discover

Answer 14

1912 - The neutron

Question 15

What is an atom

Answer 15

A small particle that makes up all objects

Question 16

What is a element

Answer 16

A substance made of one atom/molecule. These are all on the periodic table

Question 17

What is a compound

Answer 17

A mixture of 2 or more elements chemically bonded

Question 18

What is a mixture

Answer 18

A blend of elements and/or compounds that aren’t chemically bonded

Question 19

What is valency

Answer 19

Describes how easily an atom or radical can combine with another chemical species. This is determined by the number of electrons gained, lost or shared if it reacts with another atom

Essentially it is the bonding of atoms to gain full outer shells

Question 20

What is an ion

Answer 20

Any atom or group of atoms that bear one or more + or - charges
+ = cations
- = anions

Question 21

What is electronic structure

Answer 21

Also known as electronic configuration, it is how the electrons arrange themselves in shells

Question 22

What is covalent bonding

Answer 22

Shared electrons between 2 non-metals

Question 23

What are small molecules

Answer 23

Contains a few bonded atoms
Eg methane, ammonia, chlorine molecule

Question 24

What are Giant structures

Answer 24

Millions of atoms that are joined together
Eg graphite, diamond, silicon dioxide

Question 25

What is metallic bonding

Answer 25

Metal and metal with sea of delocalised electrons which can carry a charge

Question 26

What are the properties of a pure metal

Answer 26

Soft, arranged in layers that slide over each other which makes them malleable

Question 27

What is an alloy

Answer 27

A mixture of different metals which often gives high melting points, good conductivity of electricity and thermal energy and malleability

Question 28

What is a soluble

Answer 28

A substance that can dissolve in a liquid

Question 29

What is a solute

Answer 29

A solid that cannot dissolve

Question 30

What is insoluble

Answer 30

A substance that cannot dissolve in a liquid

Question 31

What is a solution

Answer 31

What is made when a solid dissolves into a liquid

Question 32

What is the solvent

Answer 32

The liquid that the solid dissolved into

Question 33

What does a reaction between metal and acid create

Answer 33

METAL + ACID -> SALT + HYDROGEN

Question 34

What test is used for hydrogen

Answer 34

The squeaky pop test

Question 35

What is chemical etching

Answer 35

A process that changes the texture of a surface with alter roughness and increase bonding effectiveness and can make it facilitate retention of oils or the opposite

Question 36

What is electrolysis

Answer 36

The process by which ionic substances in a compound become disassociated when an electrical current is passed through it

Question 37

What is the process of electrolysis

Answer 37

When a soluble ionic compound dissolves in water the lattice breaks up. The ions separate and are free to move. They can carry electrical charge through the solution making it conduct electricity

Question 38

What is disassociation

Answer 38

A reversible process of separation of charged particles in a compound. It involves separating metal from ore

Question 39

What is anodising

Answer 39

An electrolytic passivation process used to increase the thickness of oxide layer on the surface of a metal

Question 40

What is electro plating

Answer 40

Application of electrolytic cells in which a thin layer of metal is deposited onto an electrically conductive surface. The electrodes of a cell are held apart from one another

Question 41

What are galvanic protection

Answer 41

A way to protect iron or steel from rusting by applying a zinc coating as a sacrificial anode

Question 42

What is a cell

Answer 42

A chemical energy store. They transfer chemical energy to electrical by a chemical reaction

Question 43

What is an electrode

Answer 43

The metal in a battery

Question 44

What is newtons 1st law?

Answer 44

If the forces acting on an object are balanced the it will be at rest or move at a constant speed if it’s moving

Question 45

What is a lever

Answer 45

A simple pivot machine that acts as a force multiplier

Question 46

What is a moment

Answer 46

The applied force produces a turning effect called a moment when acting on a pivot point.

Question 47

What is the principal of moments

Answer 47

For a lever to be balanced the sun of the clockwise moments must equal the sim of the anti-clockwise moments

Question 48

What is a torque

Answer 48

A moment that causes rotation about an axis

Question 49

What conditions are necessary for equilibrium

Answer 49

1) the net external force is zero 2) the net external torque is zero