Radioactivity Flashcards
Isotopes
atoms of the same element that have the same atomic number but different mass number
Radioactivity
the spontaneous decay of a unstable nucleus with the emission of alpha, beta or gamma particles
radioisotopes
radioactive isotopes
what was the contibution of Henri Bequerel
discovered radioactivity
who discovered raioactivity
henri bequerel
Who discovered ratioactive elements
Perrie and Marie Curie
what did Perrie and Marie curie discover
Radioactive element polonium and radium
Name the three types of nuclear radiation
alpha radiation
beta radiation
Gamma radiation
Describe the make up alpha particles
2 protons and 2 neturons emitted by an radioactive isotope in an attempt to become stable.
identical to helium nucleus
what occours when somthing undergoes alpha decay?
Atomic no. -2
mass no. -4
a new element is formed
Describe alpha particles and give an application
Double positive charge
Relativity large mass
Slowest out of the types
Low penetrating power, not dangerous (piece of paper)
Attracted towards a negative plate
Americium 241- smoke detector
Describe the make up of Beta perticles
electrons emitted by a radioactive isotope in an attempt to become stable
-1 negative charge
Describe how beta decay occours
a netron in the nucleus splits into a proton and an electron. The proton remains in the nucleus but the electron is emitted as a beta particle
What occours when an element undergoes beta radiation
atomic no. +1
no change in mass
new element formed
describe the properties of beta particles and give an application
Negative charge
Low mass
Travel quickly
High penetrating power (5mm Aluminium)
Attracted to a positive plate in a magnetic field
Carbon-14 used in carbon dating
What is Gamma radiation?
High energy electromagnetic radiation emotted by radioactive isotopes in an attempt to become stable
What occours when an element undergoes gamma radiation?
the structure of the nucleus remains the same it loses energy to become more stable
Describe the properties of gamma radiation and list an example
Electromagnetic radiation
No charged particles
No mass
High penetrating ability ( thick lead)
Not effected by electric fields
Cobalt 60 used in radiotherapy
compare chemical and nuclear reactions
Chemical
Involves electrons rather than the nucleus
No new element formed
No release of nuclear radiation
Chemical bonds broken and formed
Nuclear-
Involves nucleus
New element formed
Release of nuclear radiation
No chemical bonds broken and formed
What is background radiation
ratiation naturally in the enviorment
name sources of background radiation
radon gas from rocks
all food ( plants absorbs radioactiv material)
cosmic rays from sun
Name health hazard of radiation
alpha/beta/ gamma are ionising.
In our clees they damage DNA, causing mutationd
Name percautions when working with radiation.
Store in Lead container
minimse time spent
maxmise distance from them
wear ppe
What instrument can detect radiation?
Geiger-Muller tube (G-M tube)
What is half life
time taken for half of the nuclei in an radioisotope to decay
Radioisotope uses
Smoke alarms: Americium 241-alpha
Carbon dating : Carbon 14- beta
Radiotherapy: Cobalt 60- Gamma
Describe Carbon dating
All living things have a fixed amount of C12:C14 - The same as the atomsphere.
When th When the organism dies, the C-12 to C-14 ratio in the organism
will change as the carbon-14 decays and decrease. The new ratio and the half-life of carbon-14 can be used to
calculate the age of the organism/objects.
What is transmutation
The changing of one element into a another
What is the half life for americum 241?
432 years…
