GCSE-Unit1 Flashcards
1
Q
The amount of material in an object is called its …?
A
Mass
2
Q
Weight is a downward …?
A
FORCE
3
Q
Weight = mass x …??
A
Gravity Strength (g)
4
Q
Alpha Decay Equation for Uranium-238
A
²³⁸U₉₂ → ²³⁴Th₉₀ + ⁴He₂
5
Q
What happens to A in any Alpha Decay?
A
A decreases by 4
6
Q
Alpha Particle Atomic Mass Number
A
4
7
Q
Equation for the Moment of a Force
A
moment of force = force x perpendicular distance from pivot
8
Q
Beta particle range in air
A
several metres.
9
Q
Beta particle ionising power
A
moderately ionising.
10
Q
Beta particles can be stopped by
A
5mm of Aluminium
11
Q
half-life of a radioactive isotope is…
A
the time taken for its activity or undecayed mass or number of undecayed nuclei to fall by half
12
Q
Atomic mass number of a neutron
A
1
13
Q
Finding acceleration from a velocity time graph
A
acceleration = gradient of line
14
Q
Finding speed from a distance-time graph
A
speed = gradient
15
Q
Gamma ray charge
A
Zero
16
Q
Beta Decay equation for carbon 14
A
¹⁴C₆ —> ¹⁴N₇ + ⁰e₋₁
17
Q
Gamma Ray Ionising Power
A
Very weak
18
Q
v-t graph shape for uniformly accelerated motion from rest
A
Straight line through origin
19
Q
Newton’s First Law of Motion
A
Every object continues in its present state of rest or uniform motion in a straight line unless it is acted upon by external unbalanced forces.
20
Q
Equation linking initial velocity and final velocity with acceleration
A
v = u + at
21
Q
How A changes in Gamma Decay
A
no change
22
Q
How A changes in beta decay
A
no change
23
Q
A beta particle is a …
A
fast moving electron
24
Q
Alpha Particles can be stopped by as little as a…?
A
sheet of paper
25
The centre of gravity of an object is the...
point through which all of its weight appears to act.
26
Alpha Particle Ionising Power
Very strongly ionising
27
Nuclear Fission is the process in which a... ?
large nucleus absorbs a neutron, splits into two smaller nuclei, releasing energy and 2 or 3 neutrons
28
displacement from a velocity time graph
displacement = area under graph
29
The plum-pudding model of the atom pictures.....
negative electrons embedded in a sphere of positive charge
30
Alpha Particle Charge
2
31
Lightest Hydrogen Isotope
Protium ¹H₁
32
Medium mass Hydrogen isotope
Deuterium ²H₁
33
Heaviest Hydrogen isotope
Tritium ³H₁
34
Gamma decay equation for Nickel-60
⁶⁰Ni₂₈*→⁶⁰Ni₂₈+γ
35
Beta Particle Charge
-1
36
Nuclear fission equation for Uranium-235
²³⁵U₉₂ + ¹n₀→ ¹⁴²Ba₅₈ + ⁹¹Kr₃₆ +3¹n₀ + Energy
37
Equation for nuclear fusion of Deuterium and Tritium
D + T → ⁴He₂ + ¹n₀ + Energy
38
Isotopes have the same number of...?
protons
39
Isotopes have different numbers of...?
neutrons
40
The S-t graph for uniformly accelerated motion is a ...?
curve
41
As time increases the S-t graph for uniformly accelerated motion becomes...?
steeper
42
Density = ...???
Mass/Volume
43
Principle of Moments
For any object in equilibrium: total clockwise moment = total anticlockwise moment
44
The moment of a force is measured in...?
Newton metres (Nm)
45
The separation of molecules in a solid is...?
very small
46
The way molecules in a solid move
they vibrate about fixed positions
47
The separation of molecules in a liquid is...?
almost as small as in a solid
48
The way molecules in a liquid move
they move around amongst each other
49
The separation of molecules in a gas is...?
very large
50
Molecules in a gas move...?
independently, rapidly and randomly
51
The Bohr-Rutherford model of the atom pictures all of its positive charge and most of its mass in the...?
nucleus
52
The Bohr-Rutherford model of the atom pictures the electrons in...?
allowed orbits around the nucleus
53
Alpha particles have a range in air of a few ...?
cm
54
The atomic mass number of a proton is ...?
1
55
The charge of a proton is...?
1
56
The atomic mass number of an electron is ...?
0
57
The charge of an electron is ...?
-1
58
The charge of a neutron is...?
0
59
An Alpha particle is a ...?
Helium nucleus
60
The atomic mass number of a beta particle is ...?
0
61
A Gamma ray is ...?
an electromagnetic wave
62
The atomic mass number of a Gamma ray is ...?
0
63
The range in air of Gamma radiation is ...?
extremely large
64
Gamma radiation is greatly reduced by a ...?
thick block of Lead or concrete
65
What happens to Z in any Alpha Decay?
Z decreases by 2
66
How Z changes in Beta decay
Z increases by 1
67
How Z changes in Gamma Decay
no change
68
After a time of n half-lives the activity of a radioactive source will equal the original value divided by ...?
2ⁿ
69
Nuclear Fusion is the process in which ...?
light nuclei join to form a heavier nucleus and release energy
70
Equation for average speed
average speed = distance travelled / time taken
71
Equation linking displacement with initial and final velocities and time
S = 1/2 (u+v) t
72
Newton's second law of motion
RF = ma
73
The equation linking work or energy (E) with power (P) and time (t)
E = Pt
74
The prefix kilo (k) means...
thousand
75
The prefix Mega (M) means...
million
76
The prefix milli (m) means...
thousandth
77
The prefix micro (µ) means...
millionth
78
The unit for power
Watt (W)
79
The equation connecting corrected activity with measured activity in a radioactivity measurement.
corrected activity = measured activity - background activity
80
Form of Newton's second law of motion involving momentum
RF = (mv-mu)/t
81
Units for momentum
kgm/s or Ns
82
Equation defining momentum
Momentum = mass x velocity
83
Impulse - Momentum equation
Change in Momentum = Resultant Force x Time
84
The conservation of momentum in a perfectly inelastic collision can be written as...
m₁u₁ +m₂u₂ = (m₁ + m₂) v
85
The conservation of momentum can be expressed as an equation, e.g with two masses as...
m₁u₁ + m₂u₂ = m₁v₁ +m₂v₂
86
In circular motion the direction of the velocity is.....
at a tangent to the orbit
87
In circular motion the acceleration acts.....
towards the centre
88
In circular motion the total force acts...
towards the centre
89
The centripetal force needed in circular motion increases if you increase...?
mass or velocity
90
The Principle of Conservation of Energy says that energy can ...?
change form
91
The centripetal force needed in circular motion decreases if you increase...?
radius
92
All objects moving freely through the air (ignoring air resistance) have the same...?
acceleration
93
The direction of the acceleration due to gravity is always ...?
vertically downwards
94
On Earth the size of the acceleration due to gravity is always ...?
10 m/s²
95
Newton's Third Law of Motion says that if an object A exerts a force on object B, the object B exerts ...?
an equal and opposite force on object A
96
Defining equation for work done
W = Fs
97
equation for percentage efficiency of a device or process
percentage efficiency = 100 x useful energy output / energy input
98
Defining equation for kinetic energy
KE = 1/2 x mv²
99
Defining equation for gravitational potential energy
GPE = mgh
100
The unit for work or energy is the ...?
Joule (J)
101
The Principle of Conservation of Energy says that energy cannot be ...?
created or destroyed
102
The unit for mass is the ...?
kilogram
103
Weight is the force caused by ...?
gravity
104
The unit for weight is the ...?
Newton
105
The unit for g is the ...???
Newton per kilogram (N/kg)
106
The experimental variable that you directly change is called the ...?... variable.
independent
107
The experimental variable that you expect to change as a result of any change you make in the independent variable is called the ...?... variable
dependent
108
Any experimental variable that you keep constant during the experiment to prevent it influencing the results is called a ...?... variable
controlled
109
An experiment that truly tests your hypothesis is ...?
valid
110
If your results are repeatable and they provide strong evidence for your conclusion then your results are ...?
reliable
111
For results to be reliable they will need to cover a ...?... enough range.
wide
112
Increasing the number of results will ...?... the reliability
increase
113
Repeating measurements will increase their ...?
reliability
114
Repeated measurements that are clumped around the true value of the variable are ...?
accurate
115
Repeated measurements that are close to each other are ...?
precise
116
If the dependent variable is always equal to the independent variable multiplied by some constant then the variables are ...??
directly proportional
117
If two variables (x and y) are directly proportional then a graph of one plotted against the other will be a ...?????
straight line through the origin
118
If two variables (x and y) are directly proportional then one divided by the other will always approximately equal a ...?
constant
119
When repeated measurements are equally spread above and below the true value the uncertainty is ...?
random
120
When repeated measurements are either all above or all below the true value the uncertainty is ...
systematic
121
If two variables (x and y) are indirectly proportional then a graph of one plotted against the other will be a ...?????
1/x type curve in which y decreases as x increases
122
If two variables (x and y) are indirectly proportional then a graph y plotted against 1/x will be a ...?????
straight line through the origin.
123
If two variables (x and y) are indirectly proportional then a constant will be obtained by... ? ...y by x.
multiplying
124
If two variables (x and y) are indirectly proportional then the equation connecting them is ...
y = k/x
125
If two variables (x and y) are directly proportional then the equation connecting them is...
y = kx
126
If two variables (x and y) are directly proportional then a constant is obtained by ...?... y by x
dividing
127
If two variables (x and y) are directly proportional then the constant of proportionality equals the ...?... of a graph of y against x.
gradient
128
If two variables (x and y) are indirectly proportional then the gradient of a graph of y against 1/x equals...????
the constant of proportionality
129
The source of a star's energy.
Nuclear Fusion.
130
Factors making fusion desirable as an energy source.
1. Could produce enough energy to meet world needs.
2. Fuel (Deuterium and Tritium) plentiful in seawater.
3. Emits no greenhouse gases.
131
Energy released per kg in nuclear fusion is what multiple of the energy released per kg in chemical reactions like burning oil?
4 million
132
Energy released per kg in nuclear fusion is what multiple of the energy released per kg in Nuclear Fission?
4
133
Problems with nuclear fusion as an energy source.
1. Difficult to achieve.
2. Expensive to develop.
134
When at least one neutron released by a fission goes on to cause another fission, it creates a ...?
chain reaction.
135
Current nuclear power stations rely on nuclear ...?
fission
136
Safety precautions with radioactive materials.
1. Keep sources in Lead-lined containers.
2. Minimize the time exposed to the radiation.
3. Use tongs to keep the source as far away as possible.
4. Wear protective clothing.
137
Uses of gamma radiation
1. Finding the route of underground pipes
2. Monitor the thickness of metal sheet during making.
3. Sterilizing syringes
4. Checking body organ function using tracer isotope.
5. Killing bacteria on food, to increase shelf-life.
138
The type of nuclear radiation used in a smoke alarm.
Alpha radiation.
139
Sources of background radiation.
1. Radioactive materials in rocks and soil.
2. Cosmic rays
3. Medical X-rays
4. Radioactive waste
5. Radioactive fallout
140
The kind of nuclear radiation that cannot penetrate the skin from the outside and so damage cells inside the body.
Alpha
141
In the Rutherford Alpha-Particle Scattering experiment, what were the alpha particles fired at?
Thin sheets of metal foil.
142
In the Rutherford Alpha-Particle Scattering experiment, what was shown by the fact that most Alpha-particles were not deflected?
Most of the volume of the atom was empty space.
143
In the Rutherford Alpha-Particle Scattering experiment, what was shown by the fact that there were a few very large deflections, including some straight back along the original path?
Most of the atom's mass and all of its positive charge was concentrated in a tiny volume (the nucleus).
144
The three methods of heat transfer
Conduction
Convection
Radiation
145
Solid, liquid and gas in order of increasing ability to conduct heat.
Gas (worst)
Liquid
Solid (best)
146
The best kind of solid at conducting heat.
Metal
147
The kind of heat transfer that spreads heat through a liquid or a gas.
Convection
148
Metals are the best conductors of heat because they have ...?
free electrons
149
The kind of surface that is a good emitter and absorber of heat radiation.
Matt black
150
The kind of surface that is a bad emitter and absorber of heat radiation.
Shiny and light-coloured.
151
The amount of energy needed to lift a typical apple through 1m is approximately ...?
1 Joule
152
A gas is less dense than a solid because its particles are ...?
further apart
153
Two ways to make an object more stable.
1. Lower its centre of gravity.
2. Increase the area of its base.
154
What is pressure?
It is the force acting per square metre perpendicular to the force.
155
What is the standard unit of pressure?
The Pascal (Pa) 1Pa = 1N/square metre
156
The pressure equation
P = F/A
157
Hooke's Law in words
The extension of a spring is directly proportional to the applied force provided the limit of proportionality is not exceeded.
158
Equation for Hooke's Law
F = ke
159
What property of a graph of Force against extension for a spring gives you the spring constant?
The gradient
160
The weight of a 1kg mass on Earth is ...?
10N approximately
161
Calculating average velocity
average vel. = displacement/time = 1/2(u+v)
162
What does a graph of F against e for a spring look like?
It is a STRAIGHT LINE THROUGH THE ORIGIN.
163
How to calculate the total spring length from the extension.
Total Length = Unstretched Length + e
