Chapter 8 : Radioactivity

RACDIhOaAptCerTI8VITY
by:ramees

dictionary

Name: Rameeswary a/p Chandran Mohan
Class: 3 DLP (2022)
Subject : Science
Sir`s name: Mr.Kumar a/l Perumal
School: SMK Dato Zulkifli Muhammad

Atom

Atoms originate from the word 'atomos' which means indivisible.
An atom is a partical of matter that uniquely defines a chemical elemnt.

Beta

Beta particles are high energy, high speed electrons or positrons that are
ejected from the nucleus by some radionuclides during a form of radioactive
decay called beta-decay.

Cosmicray

Cosmic rays are a form of high-energy radiation that originate from outside our
solar system.

Defence

Radioactive substances can be used in the field of defence such
as the nuclear bomb.

Beside heat, radioactive released from the explosion of a nuclear bomb
destroys almost all living things including human and its effect exists for
generations.

Electron

Electron is a stable subtomic particles with a charge of negative electricity.

It can be seen in all atoms and acting as the primary carrier of electricity in solids.

Food preservation

The Radura logo is used to label food preserved using radioactive radiation such
as gamma rays.
Gamma rays are used in the preservation of food such as fruits to kill bacteria in
the food.

Gamma ray

Gamma ray, electromagnetic radiation of the shortest wavelength and highest
energy.

Henri Becquerel

Antoine Henri Becquerel was a French engineer, physicist, Nobel
laureate, and the first person to discover evidence of radioactivity.

Ion

An ion is an atom or group of atoms that has an electric charge. Ions with
positive charge are called cations. Ions with a negative charge are called anions.

Joliot Curie

In 1932, Joliot Curie and her husband Frederic had full access to Marie`s
polonium. Experiments were done using gamma rays to identify the positron.

Kilogram

Kilogram is S.I.unit of mass (equivalent to appromaximately 2.2051b), first
introduced as a unit of mass metric system.

Lead

Lead is a chemical element with the symbol Pb and atomic number 82.1t is a
heavy metal that is denser than most common materials. Lead is soft and
malleable, and also has a relatively low melting point.When freshly cut,lead is a
shiny gray with a hint of blue. It tarnishes to dull gray color when exposed to air.

Microsievert

The MICROSievert is a unit in the International System of units intended to
represent the stochastic health risk of ionizing radiation.

Nuclear accidents

A nuclear and radiation accident is defined by the international Atomic Energy
Agency as "an event that has led to significant consequences to people, the
environment or the facility.

Picthblende

A pitchblende form of the mineral uraninite occurring in brown or black
masses and containing radium.

Quantity

Quantity is amount or number of a material or abstract thing not usually
estimated by spatial measurement.

Radioactivity

Radioactivity is a act of emitting radiation spontaneously.

Spectrum

A spectrum is defined as the characteristic wavelengths of electromagnetic
radiation (or a portion there of) that is emitted or absorbed by an object or
substance, atom, or molecule.

Thorium

Thorium is a weakly radioactive metallic chemical element with the symbol
Th and atomic number 90.

Uranium

Uranium is a silvery-white metallic chemical element in the periodic table, with
atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92
protons and 92 elctrons, of which 6 are valence electrons. Uranium has the highest
atomic weight of all naturally occurring elements.

Wilhelm Conrad Roentgen

Wilhelm Conrad Roentgen was a German mechanical engineer and physicist,who,
on 8 November 1895, produced and detected electromagnetic radiation in a
wavelength range known as X=rays or Rontgen rays, an achievement that earned
him the inaugural Nobel Prize in Physics in 1901.

X-ray

X-rays are a form of electromagnetic radiation, similar to visible light.

Year

Civil year the period of time, the calendar year, containing 365 days or
in a leap year 366 days.

end of dictionary Page 11 of 11

The End

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