Chapter 4: Atomic Structure

Contamination

________ is especially dangerous because radioactive particles could get inside your body.

Thomson

________ suggested atoms were spheres of positive charge with tiny negative electrons stuck in them like fruit in a plum pudding- the plum pudding model.

Nuclear equations

________ are a way of showing radioactive decay by using element symbols.

Radioactive substances

________ give out radiation from the nuclei of their atoms- no matter what.

Gloves

________ and tongs should be used when handling sources, to avoid particles getting stuck to your skin or under your nails.

Gammas rays

________ are a way of getting rid of excess energy from a nucleus.

beta particle

For every ________ emitted, a neutron in the nucleus has turned into a proton.

Beta decay

________ increases the charge of the of the nucleus.

Radiotherapy

________- treating cancer with radiation.

Niels Bohr

________ said that electrons orbiting the nucleus do so at certain distances called energy levels.

proton

A(n) ________ is positively charges and a neutron is neutral, so the charge of the nucleus decreases.

Radiation

________- emitting implants can also be put next to or inside tumours.

Exposure

________ to radiation is called irradiation.

Lower doses

________ tend to cause minor damage without killing the cells.

Gamma sources

________ are usually used in medical tracers.

Half life

________ can be used to find the rate at which a source decays- its ACTIVITY.

short half life

A(n) ________ means the activity falls quickly, because the nuclei are very unstable and rapidly decay.

splits

Two or three neutrons are also released when an atom ________.

Rutherford

________ replaced the plum pudding model with the nuclear model.

high speed

Two light nuclei collide at ________ and join to create larger, heavier nucleus.

mass numbers

They can also release neutrons when they decay, as they rebalance their atomic and ________.

1804

In ________, John Dalton agreed with Democritus that matter was made up of tiny spheres that couldnt be broken up, but he reckoned that each element was made up of a different type of atom.

Radioactivity

________ is a totally random process.

Isotopes

________ are different forms of the same element.

radioactivity of a source

The ________ decreases over time.

strongest reading

A computer converts the reading to a display showing where the ________ is coming from.

Fusion

________ released a lot of energy.

Alpha decay

________ decreases the charge and mass of the nucleus.

separate light nuclei

Heavier nucleus produced does not have as much mass as the two ________ did.

high doses

Since ________ of ionising radiation will kill all living cells, it can be used to treat cancers.

particle

A a- ________ is two neutrons and two protons.

chain reactions

Uncontrolled ________ quickly lead to lots of energy being released as an explosion- this is how nuclear weapons work.

Background radiation

________ is the low- level radiation thats around us all the time.

nuclear model

The ________ that resulted from the alpha particle scattering experiment was a positively charged nucleus surrounded by a cloud of negative electrons.

Nuclear fission

________- splitting a large, unstable nucleus.

Beta sources

________ are less damaging inside the body, as radiation is absorbed over a wider area, and some passes out of the body although.

Nuclear fusion

________ is the opposite of nuclear fission.

radiation doss

The ________ tells you the risk of harm to body tissues due to exposure to radiation.

Alpha particles

________ are helium nuclei.

Alpha radiation

________ is when an alpha particle is emitted from the nucleus.

nuclear equations

In ________, an alpha particles can be written as a helium nucleus.

Beta particles

________ have virtually no mass and a charge of- 1.

Contamination

________ is radioactive particles getting onto objects.

beta decay

When ________ occurs, a neutron in the nucleus turns into a proton and releases a fast- moving electron.

Gamma rays

________ are directed carefully and at just the right dosage to kill the cancer cells without damaging too many normal cells.

Radiation

________ from space, which is known as cosmic rays.

Gamma sources

________ are the least dangerous inside the body, as they mostly pass straight out- they have the lowest ionising power.

Radioactive substances

________ spit out one or more types of ionising radiation from their nucleus- the ones you need to know are alpha, beta and gamma radiation.

background radiation

The dose from ________ is small, so millisieverts are often used.

Gamma rays

________ are waves of electromagnetic radiation released by the nucleus.

Risks

prolonged exposure to radiation poses future risks and causes side effects

Benefits

can get rid of cancer entirely