physics

Ionising

Enough energy to remove electrons from atoms/molecules

Repeats meaning

At each interval we measure more than once which reduces errors

Dalton

Solid sphere

Repeatable

You do it to achieve the same results

Reproducible

Other people do it to get similar results

Systematic errors

Instrumental

Observational

Environmental

Random errors

Obersvation being too high low

Instrumental readings fluctuate

Resolution of measuring instrument

Smallest change in the quantity being measured that gives a perceptible change in the reading

Current

Different particles

Small nucleus

Small

Beta particles

Atom mass

Stays the same

Atomic number

Increases

Atoms charge

Changes

Alpha particle

Atoms mass

Decreases

Atomic number

decreases

Gamma

Atoms mass

Stays the same

Atomic number

Stays the same

Arrangement of particles in nucleus

Changes

Method of finding the mass of an irregular object

1 use the mass balance to find the blocks mass

2 fill your displacement can fully at the edge of the sink and allow it to stop dripping water from the spout

3 put your measuring cylinder under the spout of the displacement can

4 place your object at the surface of the water and lower it gently to the can

5 measure the volume of the water displaced

1ml =1 cm³

6 calculate the density using the formula : density=mass % volume

What is beta radiation

A high speeding electron

What happens if u reverse the cells

The reading becomes negative

Natural background radiations

Cosmic rays

Food

Rocks

Radon gas

What is a gamma ray

Electromagnetic radiation from nucleus

When is a beta particle produced

When a name from I’m the nucleus turns into a proton and releases a fast moving electron

Man made background radiation

Medical imaging and treatment

Nuclear power stations

Nuclear weapons

Industrial processes

Main source of background radiation is

Radon gas

What is proportional

When two factors increase in line with each other

Total clockwise moment equals what

Total anticlockwise moment

What is a pivot

Point around which something turns

Moment of a force is

A measure of the turning affect on an object

What does the size of a moment depend on

The size of the applied source

The perpendicular distance from the force to the pivot

How can we increase the moment without increasing the force

Apply the force further away from the pivot

Activity symbol

Bq

Hookes law

The extension of a spring is directly proportional to the force applied

Directly proportional meaning

Straight line through a graph (0,0)

Thermistor has a high resistance at

Low temperatures

Radioactive decay is what

Unstable nucleus splitting randomly

What does a Geiger muller tube detect

Background radiation in photographic filming

An alpha particle is the same as what

Helium atom (2 protons and 2 electrons)

What is magnitude

Measurement or great value of quantity

Elastic

A material that returns to its original shape after the forces of bending and stretching are removed

Inelastic

A material that retains its new shape after the forces of bending and stretching are removed

Elastic potential equation

2

Ep=1/2 x K x X

In parallel circuits the potential difference is the same to what

The supply potential difference

Th current in a diode is what

Directly proportional to potential difference

Increasing a filaments temperature does what

Increases the energy of the ions metal wire

What is work

Transfer of energy from one store to another

Work fact in joule

One joule of work is done when one newton force moves an object one metre

What did Mendeleev do

Left gaps for undiscovered elements

Made predictions about the properties of undiscovered elements

Predictions were true

Chemical properties of transition elements and group 1 elements

Form coloured ions

Very unreactive ( only silver and gold)

Used as catalysts

Why are things unreactive

They have a full outer shell so don’t need to react with anything else

A beta particle is emitted and when formed does what

A nucleus with a -1 charge and turns into a proton and electron

Chain reaction

Constant triggering to continue , there must be enough uranium to prevent neutron escape critical mass

Induced fission

Man made process of nucleus splitting into two large fragments

Spontaneous fission

Natural reactions occurring daily

Plum pudding

General ball of positive charge with electrons embedded throughout

Half life

Time taken for half radioactive nuclei to decay or count rate to fall to its units level

Radioactive irradiation

Exposure to radiation (when radiation produce the source stops and is not radiated )

Contamination

Radioactive sources enter and produce for thousands of years

Fusion

Two light atomic nuclei joining together to form heavier nucleus releasing large amounts of energy

Background radiation

Radioactive materials occur naturally so everyone is exposed to low levels of radiation

Particle charge mass

Mass

Protons + neutrons

Atomic

= protons

Number of n

Atomic - mass

Nucleus

Made of protons and neutrons and positively charged due to protons

Dense

Contains nearly all mass of an atom in a tiny space

Element

Single type of atom

Isotope

Atoms of the same element have same protons but varied number of neutrons

Ionisation

Atoms have the same amount of protons and electrons so no overall charge

Irradiation

Radiation to subject which moves away and radiation is no longer contaminated

Ionization

Atoms lose one or more outer electrons to become positive

nuclear fission

Splitting of large unstable nucleus normally in the stars or sun

Moderator

Slows down neutrons

Series circuit

End to end

Current splits between the branches

Voltage is shared

Resistance is the sum of all

Potential difference is shared

Parallel

Side by side

Voltage is the same

Resistance is less than the smallest resistor

Beta (a)

Medium energy

Medium mass

Medium ionising effect

Unstable nucleus emits fast moving electrons

Gamma (B)

Highest energy

No mass as it’s waves

Least ionising effect

When too much energy is emitting a gamma wave without changing its mass or composition

Decreasing the current does what

Increases resistance

Potential difference

Measure of charge

Charge unit

Coloums

Boiling point of water

100*c

water melting point

0*c

Thermistor

Semi conductor which conducts more when heated

LDR

Resistance changes with its light intensity

Bright is low

Dark is high

JJ Thompson

Discovered the electrons and developed plum pudding model of atoms

Chadwick

Developed nuclear model

Bohr

Electrons surround nucleus in large orbits

John

Formed atomic theory which is matter is made of tiny indestructible particles with the same atomic weight

Democritus

All mater made of atoms which are invisible and so small they can’t be divided

Rutherford

Uses gold foil experiment to state all mass is small and charged ball at the centre of an atom

Ohms law

Current is directly proportional to potential difference

Power

Energy transferred from electrics, source to the appliance per second

Electrical resistance

Opposition to flow of charge (OHMS)