Physics Flashcards
1
Q
What is most of an atom?
A
empty space
2
Q
Where is all of an atoms mass concentrated?
A
In the nucleus
3
Q
What did Rutherfords Experiment involve?
A
It involved firing positively charged alpha particles at a thin peice of gold foil
4
Q
How many alpha particles bounced back in Rutherfords Experiment?
A
1 in 800
5
Q
What did the Rutherford Scattering Experiment conclude?
A
That an atom is made up of a small, positively charged nucleus surrounding by electrons orbiting it.
6
Q
Who made the plum pudding model?
A
J.J. Thomson’s
7
Q
What is the plum pudding model?
A
negatively charged electrons surrounded by a sea of positive charge
8
Q
What did Niels Bohr discover?
A
He adapted to the nuclear model by suggesting that electrons orbit the nucleus at specific distances, called energy levels.
9
Q
What did James Chadwick discover?
A
the existence of neutrons within the nucleus
10
Q
How do you find the atomic mass number?
A
protons + neutrons
11
Q
How do you find the amount of protons and electrons ?
A
the atomic number = the protons and electrons
12
Q
What is an Isotope?
A
An atom with the same number of protons and a different number of neutrons.
13
Q
Why are Isotopes identical in their chemical reaction?
A
because they have the same number of protons and electrons
14
Q
What is Radioactivity?
A
Some Isotopes are radioactive meaning they are unstable as they have too many neutrons.
15
Q
What is Ionisation?
A
When radiation knocks electrons off of atoms
16
Q
Why is Ionisation dangerous?
A
It is dangerous as it can harm DNA.
17
Q
What is Radioactive Decay?
A
Is when a nucleus of an atom emits alpha, beta or gamma radiation
18
Q
What are the 3 types of Radioactive Decay?
A
Alpha Decay, Gamma Decay, Beta Decay
19
Q
What is a alpha particle?
A
2 protons and 2 neutrons. the same as a helium nucleus
20
Q
What is a beta particle?
A
Is a high energy electron emmited from the nucleus when a neutron turns into a proton.
20
Q
What is gamma radiation?
A
Is a high energy electromagnetic radiation wave, not a type of particle
21
Q
What is an Alpha Particles charge and mass?
A
Charge = +2 Mass = 4
22
Q
What is a Beta Particles charge and mass?
A
Charge = -1 Mass = 0
23
Q
What is the charge and mass of Gamma Radiation?
A
Has no mass or charge
24
What is an alpha particle stopped by?
paper
25
What is a beta particle stopped by?
5mm of aluminum
26
What stops gamma radiation?
5cm of lead
27
How penetrating and ionising is an alpha particle?
How Penetrating = Low
How Ionising = High
28
How penetrating and ionising is a beta particle?
How Penetrating = Medium How Ionising = Medium
29
How penetrating and ionising is gamma radiation?
How Penetrating = High
How Ionising = Low
30
What is an Alpha Decays Equation?
The helium stays the same and the:
Mass Number decreases by 4
Atomic Number decreases by 2
31
What is a Beta Decays Equation?
The "e"(electron) stays the same:
Mass Number is unchanged
Atomic Number increases by 1
32
Why is the atomic mass and number unchanged in Gamma Equation?
There is no change to make up of the nucleus and so a new element is NOT formed
33
What is Neutron Emission?
It is another way of stabilising the nuclei but by emitting a neutron
34
What is Neutron Emission equation?
The "n" (neutron) stays the same:
The atomic mass decreases by 1
The atomic number is unchanged
35
What is Activity? (count rate)
Number of decays per second
36
What is a geiger counter?
The device used to measure activity
37
What is a Half-Life?
Average time taken for activity or number of radioactive nuclei to halve
38
A 1000g radioactive sample has a half life of 2 years. How much will still be radioactive after…
1. 2 years?
2. 4 years?
3. 10 years?
1. 500g
2. 250g
3. 31.25g
39
What is Net Decline?
Is the ratio of atoms which are still radioactive which can be written in fractions.
40
What is Background Radiation?
Background radiation is the low-level radiation we are exposed to every day (e.g ground,air,food,drink)
41
3 ways to reduce exposure to Radiation?
1. wearing protective clothing
2. keeping distance from sources (tongs)
3. storing sources in lead lined containers
42
What is Radiation Dose?
measures possible harm radiation could do to the body in sieverts(sv)
43
Why is Radiation so dangerous?
because it can cause ionisation which can harm DNA
44
What is Irradiation?
is when a radioactive material outside the body fires alpha, beta or gamma particles at a living thing
45
How dangerous is an alpha particle in Irradiation and Contamination?
In Irradiation it is not dangerous as it is blocked by the skin.
In Contamination it is very dangerous as it is highly ionising
46
How dangerous is a beta particle in Irradiation and Contamination?
In Irradiation it is dangerous as it can penetrate skin and damage cells.
In Contamination it is dangerous as it is Ionising but not as much as an Alpha Particle.
47
How dangerous is Gamma Radiation in Irradiation and Contamination?
In Irradiation it is not to dangerous in small quantities
In Contamination it is less dangerous as it is less ionising
48
What are the two types of circuit?
Series and Parallel circuits
49
What is the unit for current?
Amps (I)
50
What is the unit for potential difference?
voltage (volts)
51
Do the questions on Slide 3 - Lesson 2 Current in Series and Parallel (Physics)
52
What is an Electric Current?
Electric current is a flow of negatively charged particles to positively charged particles (i.e. electrons).
53
Why when a battery is connected in a circuit, electrons flow from negative to positive?
because they are repelled by the negative end of the battery and attracted by the positive end.
54
What does a Current tell us?
Current tells us how many electrons pass a point per second and we count the amount of “charge” in Coulombs (C)
55
What is a Current?
A current is a flow of charge (electrons)
56
what is the equation for current?
I = Q T I (current) Q (charge) T (time)
I and T on the bottom and Q on the top
57
What is the unit for charge?
Coulombs (C/Q)
58
A current of 20A flows transferring a charge of 210C. How long does this take?
10.5 seconds
59
The current of 5A flows through a wire for 30s, how much charge is transferred?
150 coulombs
60
One coulomb is equal to how many electrons?
1 C = 6.24 x 10(18 indice) electrons
61
What is a series circuit?
In a series circuit, components are connected in one continuous loop so if one bulbs breaks, the other will go out.
62
What is a parallel circuit?
In a parallel circuit, components are connected on separate loops so if one bulb breaks, the other will stay on.
63
What is the current in a series circuit?
The current in a series circuit is the same at any point
64
What is the current in a parallel circuit?
In a parallel circuit, the current splits up down each branch
65
What is Potential Difference measured with?
a voltmeter
66
What is Potential Difference?
Potential difference (a.k.a. voltage) is the difference in electrical potential energy charges between two points in a circuit.
67
In a circuit what makes the electrical potential difference increase?
When electrons pass through a battery
68
In a circuit what makes the electrical potential difference decrease?
When the electrons pass through other components
69
what is the equation for potential difference?
V = E Q V (Potential Difference) Q (Charge) E (Energy)
V and Q are on the bottom and E is on top
70
In a series circuit how is the potential difference done?
the potential difference splits up
71
What is a current measured in?
Amperes
72
What is the structure of metals?
It is made up of ions in a fixed position and delocalised electrons
73
What is Resistance?
Resistance is how difficult it is for current to flow through a component.
74
What is the unit for Resistance?
Ohms
75
As electrons move along a wire what happens?
they collide with the metal ions causing the ions to vibrate which makes the metal hotter.
76
Why does the length of the wire affect resistance?
As the length of the wire increases the electrons have to travel further so the chance of collision will increase causing the resistance to increase
77
What is resistance caused by?
electrons colliding with metal ions
78
Which wire would have more resistance a long thin wire or a short thick wire?
A thin wire as there not a lot of space for the electrons to go
79
What is the equation for Ohm's Law?
V = I R I (current) R (resistance) V(Potential Difference)
I and R on the bottom and V on the top
80
What is Voltage?
How much energy the electrons give or receive
81
What happens to a series circuit when you add a resistor?
the total resistance increases because all of the electrons have to pass through each of the resistors in turn.
82
What happens to a parallel circuit when you add a resistor?
The total resistance decrease because the electrons have more pathways to go take.
83
What is Equivalent Resistance?
is the idea of replacing all of the resistors in a circuit with one resistor of the same value.
84
Do the questions on slide 15 - Lesson 5 Resistance (Physics)
85
Do ws2 - mixed electricity equations
86
True or False can energy be destroyed?
False
87
what is the unit for energy?
joules
88
What is Kinetic Energy stored in?
stored in an object when it is moving
89
What is Chemical Energy stored in?
stored in fuels e.g. coal, food, batteries.
90
What is Gravitational Potential Energy stored in?
stored in objects that have a height.
91
What is Elastic Potential Energy stored in?
stored in a springy object when you stretch it.
92
What is Thermal Energy stored in?
stored in an object that has a temperature.
93
What is Light Energy stored in?
given out when an object emits light
94
What is Electrical Energy stored in?
stored in energy electrons have when they move
95
What is Nuclear Energy stored in?
stored in the nuclei of atoms
96
What is Sound Energy stored in?
given out when an object vibrates and makes a sound
97
What is Magnetic Energy stored in?
energy in magnets in electromagnets
98
Use this sentence to remember the 10 energy stores
"Most Kids Hate Learning G C S E Energy Names"
(The capital letters are the energy stores)
Magnetic,Kinetic,Heat,Light,Gravitational,Chemical,Sound,Electrical,Elastic,Nuclear.
99
What is the Conservation of Energy?
Energy cannot be created or destroyed, it can only be transferred from one store to another.
100
What happens in a closed system in conservation of energy?
Energy cannot enter or leave a closed system of objects, so the amount of energy remains constant. In reality – closed systems don’t exist.
101
Do the questions on Slide 18 and the answers are on Slide 19.
The powerpoint is called Energy Lesson 1 (Physics)
102
Do the questions on Slide 20 and the answers are on Slide 21.
The powerpoint is called Energy Lesson 1 (Physics)
103
Do the questions on Slide 22 and 23 and the answers are on Slide 24.
The powerpoint is called Energy Lesson 1 (Physics)
104
What is Work Done?
Work done is the amount of energy needed to move an object a distance against an opposing force.
105
What is the unit used for Work Done?
Joules (J)
106
What is the unit used for Force?
Newtons (N)
107
What is the equation used for Work Done?
W = F x D W (Work Done) F (Force) D(Distance)
F and D are on the bottom and W is on top
108
Do the questions on Slide 9 and the answers are on Slide 10
The powerpoint is called Lesson 2 Work (Physics)
109
Write a similar sentence for :
When a table is dragged across the ground, work is done against the force of friction. Energy is converted from kinetic to thermal.
110
In gravitational potential energy what does the gravity equal to?
9.8
111
What is the equation used to find gravitational potential energy?
GPE = m x g x h
Mass, Gravity and Height are on the bottom and Gravitational Potential Energy is on the top.
112
Do the questions on Slide 9 and the answers are on Slide 10
The powerpoint is called Lesson 3 GPE and KE (Physics)
113
Complete ws2 - Kinetic Energy Caculations(The answers are on the other side of Flashcard)
240000J
9.9J
19.84J
61364J
2.304J
40kg
80kg
4m/s
1.54m/s
114
What is the equation used for Kinetic Energy?
Kinetic Energy = 0.5 x mass x velocity squared
