WELCOME TO OUR

PRESENTATION

Name IDMd.Ashaduzzaman 131-15-2392Md. Ruhul Amin 131-15-2353Shakir Sourov 131-15-2180Fdffgfg 131-15-545Dtfgfg 131-15-njj

Presented By

OUR PRESENTATION TOPIC IS

RADIOACTIVITY

An unstable atomic nucleus emits a form of radiation (alpha, beta, or gamma) to become stable.

In other words, the nucleus decays into a different atom.

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Radioactivity

Atoms and Radioactivity

Isotopes of some elements have unstable nucleus .In order to become stable the make break apart or decay .This decay causes the nucleus to emit ionising radiation, and an atom of a different element is formed . These isotopes are called radioisotopes or radio nuclidesExample – using Carbon

A normal carbon nucleus looks like this, it has 6 protons and 6 neutrons. This is perfectly stable.

Proton

Neutron

He42

Alpha ()helium nucleus

Types of Radiation

paper2+

Beta-minus (-) electron e0

-11- lead

Gamma () high-energy photon 0 concrete

It is actually the nucleus of a helium atom consisting of 2 protons and 2 neutrons, held tightly together.It comes directly from the nucleus, so only big atoms tend to emit it.

It strongly interacts with matter around it, smashing past atoms and ionising them.

The alpha radiation, a helium nucleus (2,protons and 2 neutrons).

Alpha radiation

Beta Radiation

Is a high speed electron, given off when a neutron turns into a proton

They are many times smaller than alpha radiation .

They interact much less strongly with matter .

Beta radiation, (a high speed electron)

Sometimes a nucleus that is still unstable after a beta or alpha decay is still unstable so may emit gamma radiation to become more stable.This is an electromagnetic wave with a very short wavelength .It does not change the number of protons or neutrons in the nucleus

Gamma Radiation

Gamma Radiation, (a short electromagnetic wave)

The decay process is random. No one can predict when 1 nucleus decays. The emission is spontaneous. It is possible to make a statistical prediction.

Radioactive decay

Betas and gammas are the most dangerous they can penetrate and reach the cells of organs They are absorbed and ionise the cells This can cause cancer Alphas are the least dangerous

The danger of radiation sources - outside of the body - 1

Nuclear bomb

The gamma rays they emit can travel long distances without absorption

This has been caused by long exposure to gamma rays

Radiation burn

Alpha radiation is the most dangerous as it is strongly absorbed and ionises cells

Betas and gammas are not strongly absorbed and cause less ionisation damage

The danger of radiation sources – inside the body

Killing cells using gamma radiation

Gamma rays are used to kill cancer cells and bacteria

Electricity GenerationSterilization of hospital equipmentChecking leaks in pipesIrradiation of food

Other Uses of Radiation

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Thank you for your time .