Science Revision. Flashcards
1
Q
Osmosis Definition.
A
Osmosis is the net movement of water molecules from a high water concentration to a low water concentration through a semi-permeable membrane.
2
Q
Active Transport Definition.
A
The movement of particles/substances through a semipermeable membrane against a concentration gradient, using energy released through respiration.
3
Q
Diffusion Definition.
A
The movement of particles from an area of high concentration to low concentration.
4
Q
Photosynthesis Word Equation.
A
Carbon Dioxide + Water -> Glucose + Oxygen.
5
Q
Natural Selection.
A
There is variation in characteristics within a population. If these characteristics allow a species to survive, those with the genes will reproduce and pass them on. Over time, a new species is created.
6
Q
Who introduced the concept of Natural Selection?
A
Charles Darwin.
7
Q
Large intestine function.
A
Absorb water.
8
Q
Small intestine function.
A
Absorb nutrients, break down food and get rid of unecessary waste.
9
Q
Liver function.
A
Produces bile - triangular shape on diagrams.
10
Q
Gall bladder function.
A
Stores bile produced by the liver.
11
Q
Oesophagus function.
A
Allows passage of food from the mouth and throat to the stomach.
12
Q
Is this a plant or animal cell?
A
Plant cell.
13
Q
Is this an animal or plant cell?
A
Animal cell.
14
Q
What do plant cells have that animal cells don’t? (3)
A
Vacuoles, cell walls, chloroplasts.
15
Q
Mitochondria function.
A
Release energy for the cell via aerobic respiration.
16
Q
Nucleus function.
A
Controls the cells activities and contains the genetic material.
17
Q
Cytoplasm function.
A
Jellylike substance where chemical reactions of the cell occur.
18
Q
Cell membrane function.
A
Controls what enters/exits the cell.
19
Q
Ribosomes function.
A
Site of protein synthesis - where proteins are made.
20
Q
Cell wall function.
A
To support and strengthen the cell.
NOT FOR PROTECTION.
21
Q
Vacuole function.
A
Keeps the cell rigid and provides support.
22
Q
Chloroplasts function.
A
Contains chlorophyll where photosynthesis occurs.
23
Q
Battery symbol.
A
Converts chemical energy into electrical potential energy.
24
Q
Cell symbol.
A
Converts chemical energy into electrical potential energy.
25
Diode symbol.
Regulation of the flow of electricity, and to maintain constant voltage.
26
Voltmeter symbol.
Measures voltage/potential difference.
27
Thermistor symbol.
A resistor with a resistance dependent on temperature.
28
Resistor symbol.
A fixed resistor, so the resistance doesn't change.
29
Variable resistor.
Increases the resistance in a circuit, and reduces the current.
30
Light Emitting Diode (LED).
An LED works in a circuit by emitting light when electrical current passes through it in the correct direction.
31
Lamp symbol.
Emits light.
32
Fuse.
The fuse breaks the circuit if a fault in an appliance causes too much current to flow.
33
Ammeter.
Measures the amount of current in a circuit.
34
Light Dependent Resistor (LDR) symbol.
Used to detect light levels.
35
Potential Difference Definition.
Potential difference (voltage) is a measure of energy, per unit of charge, transferred between two points in a circuit.
36
How is Potential Difference Calculated?
V = I * R, (Voltage = Current * Resistance)
37
Which type of circuit is categorised by having one loop.
Series circuit.
38
Which type of circuit is categorized by having several loops/branches.
Parallel circuit.
39
What is current measured in?
Amperes/ Amps/ A.
40
What is voltage measured in?
Volts/ V.
41
How is resistance calculated?
R = V/I - Resistance = Voltage / Current.
42
How is charge split in a series circuit?
Charge is split across components and is equal to the voltage of the supply.
If two identical components are connected in series, the supply voltage divides EQUALLY between them.
43
How is charge split in a parallel circuit?
The total current supplied is split between the components on different loops/branches.
44
If a component breaks in a series circuit, will the rest of the circuits continue to work?
No.
45
If a component breaks in a parallel circuit, will the rest of the components continue to work?
If a component in a parallel circuit breaks, the current will still be able to travel along the other unbroken branches. Therefore, the current on the other branches will still be able to work.
46
What is the equation linking speed, distance and time?
Speed = Distance / Time.
47
Rearrange the speed, distance, time equation so distance is the subject of the formula?
Distance = Speed * Time.
48
A car travels 540km in 6 hours, i forgor the question
3 hours and 15minutes.
49
Acceleration equation.
Acceleration = change of velocity / time taken.
50
What must be used when drawing diagrams or graphs in science?
Pencil and ruler.
51
How to calculate percentage change.
difference/original x 100
52
Resultant force =
A single force which replaces several other forces.
53
What are the eight energy stores?
Kinetic, thermal, chemical, gravitational potential, elastic potential, electrostatic, magnetic and nuclear.
54
What is kinetic energy?
The store of energy in a moving object.
55
What is dissipated energy?
Wasted energy because the energy is being stored in a way that is not useful.
56
What is the law of energy conservation?
Energy cannot be created or destroyed, only transferred between stores.
57
Unbalanced forces =
When the motion of an object changes, the forces are unbalanced.
58
Balanced forces =
Balanced forces are equal in size and opposite in direction.
59
If there is a tug of war competition and 1200N is being applied on the RIGHT side, and 1400N to the LEFT side, which way will the rope move?
To the left.
60
List the contact forces.
frictional, tension, normal, air resistance, applied, spring
61
List the non-contact forces.
gravitational, electrostatic, magnetic
62
Real Men In Violet Underwear Xtremely Gorgeous.
Radio, Microwaves, Infrared, Visible light, ultraviolet, x-rays, gamma rays.
63
Right Mate I'm Very Unhappy X-factors Good.
Radio, Microwaves, Infrared, Visible light, Ultraviolet, x-rays, gamma rays.
64
How do you calculate wave speed?
Wave speed (m/s) = frequency (Hz) x wavelength (m)
65
What is the highest point of a wave called?
Peak or crest.
66
Lowest point of a wave is called the..?
Trough.
67
What is the amplitude of a wave?
The point from the middle of the wave to the crest.
68
What is the frequency of a wave?
Number of waves passing a certain point per second.
69
What energy store does an object on a shelf have?
Gravitational potential.
70
List the transverse waves?
Vibrations on a guitar string, a Mexican wave, electromagnetic waves (light, microwaves, radio waves), ripples on the surface of water, seismic S waves.
71
List the longitudinal waves?
Sound waves, primary waves of an earthquake, ultrasound, vibrations of a spring, tsunami waves.
72
What do we call a push or pull on an object?
A force.
73
Name the main resistive force that opposes the driving force when a vehicle is moving?
Friction.
74
A boat has a force of 30N to the right, and 45N to the left, what is the resultant force?
15N.
75
What unit is force measured in?
Newtons (N).
76
Equation to calculate work done?
Work done = force * distance moved in the direct of the force.
77
How much work is done if a force of 40N is used to move an object 8metres?
320J.
78
What is the unit for Work Done?
Joules (J)
79
Reactivity Series?
Potassium.
Sodium.
Lithium.
Calcium.
Magnesium.
Carbon.
Zinc.
Iron.
Hydrogen.
Copper.
Gold.
80
Reactions of metal with water.
When a metal reacts with water, a metal hydroxide + hydrogen are formed.
81
Magnesium + water ->
Magnesium hydroxide + hydrogen.
82
Reactions of metals with dilute acids.
When a metal reacts with a dilute acid, a salt and hydrogen are formed.
83
Magnesium + hydrochloric acid ->
Magnesium chloride + hydrogen.
84
Platinum is placed below gold in the reactivity series, predict its reaction with dilute acids and explain your answer?
Platinum will not react with dilute acids. Metals below hydrogen in the reactivity series do not react with dilute acids. Both gold and platinum are placed below hydrogen on the reactivity series.
85
Reactions of metals with oxygen.
Metals react with oxygen to make metal oxides.
86
Magnesium + oxygen ->
Magnesium oxide.
87
What is combustion?
The process of burning.
88
What is an exothermic reaction?
An exothermic reaction is something that gives off heat energy to its surroundings.
89
What is an endothermic reaction?
A reaction that takes in heat energy from its surroundings.
90
What is a chemical reaction?
A chemical reaction is when one or more substances change + produce one of more new chemical substances.
91
Reactants =
Chemicals involved in a chemical reaction.
92
Products =
Chemicals produced from the reaction.
93
Where are metals located on the periodic table?
Metals are located to the left of the periodic table.
94
Test for oxygen?
A glowing split will relight when inside a test tube of oxygen.
95
Test for carbon dioxide?
If carbon dioxide is present then it will turn limewater milky white.
96
Test for hydrogen?
Burns a splint with a squeaky pop.
97
A compound is
a substance, containing two or more elements that are chemically combined.
98
An element is
a substance that is made of only one type of atom.
99
Physical properties of metals?
Being shiny.
Conductors of heat.
Conductors of electricity.
Being malleable.
100
Chemical properties of metals?
Lose electrons easy in chemical reactions.
Reactive with hydrochloric acid to make hydrogen gas.
101
Dissolving + Solutions.
A solid or gas dissolved in a liquid is called a solution.
The dissolved substance is called the solute.
The liquid used for dissolving is called the solvent.
102
What is the FULL NAME for this state symbol: (aq)?
Aqueous Solution.
103
What is the colour change if starch is present in a food?
Yellow/brown -> Blue/black.
104
Which chemical is used to test for starch?
Iodine solution.
105
Colour change if lipids are present in a food?
Colourless -> MILKY white.
106
What chemical is used to test for lipids?
Ethanol solution.
107
Colour change if SIMPLE sugars are present in a food?
Blue -> CLOUDY ORANGE or BRICK RED.
108
Which reagent is used to test for simple sugars?
Benedict's solution.
109
Colour change if proteins are present in a food?
Blue -> Mauve OR purple.
110
Which reagent is used for testing if proteins are present?
Biuret solution.
111
Factors effecting reaction rate?
Temperature, substrate concentration and pH.
112
What is an enzyme?
Enzymes are proteins that function as biological catalysts. They are molecules that speed up the rate of chemical reaction without altering practical results.
113
Factors affecting photosynthesis?
Light intensity.
Carbon dioxide concentration.
Temperature.
Amount of chlorophyll.
114
Who came up with the Plum Pudding Model?
JJ Thomson
115
Who discovered electrons?
JJ Thomson
116
Who discovered the neutron?
James Chadwick
117
Who discovered protons?
Ernest Rutherford
118
Why do atoms have no overall charge?
Atoms have no overall change because they contain equal amounts of positive protons and negative electrons. They cancel each other out, and neutrons have no charge, meaning the overall charge of an atom is 0.
