Elements of Life - Atomic Structure Revision Notes

Revision notes on Element of Life, Atomic Structure part of the Specification

HideShow resource information
Preview of Elements of Life - Atomic Structure Revision Notes

First 97 words of the document:

Atomic Structure - Chapter 2 Nancy Dirar
All About Protons, Neutrons And Electrons
Introduction to atoms
The structure of an atom consists of three types of subatomic particles: protons, neutrons
and electrons.
Protons and neutrons form a dense nucleus.
Particle Mass Relative Charge
Proton 1 +1
Neutron 1 0
Electron 0.00055 -1
Isotopes
Isotopes atoms of the same element with different mass numbers. This is due to a different
number of neutrons.
Relative atomic mass is the averages of relative isotopic mass taking into account their
abundance.

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Atomic Structure - Chapter 2 Nancy Dirar
To calculate relative atomic mass use the following formula:…read more

Page 3

Preview of page 3

Here's a taster:

Atomic Structure - Chapter 2 Nancy Dirar
Radioactivity
Introduction
Unstable isotopes that have nuclei that break down spontaneously are described as being
radioactive and are called radioisotopes.
When the particles break down they emit rays and particles called emissions.
This break down of radioisotopes causing emission is called radioactive decay.
There are three types of emission ­ alpha, beta and gamma.
Alpha emissions
Alpha emissions involve helium nuclei being emitted.…read more

Page 4

Preview of page 4

Here's a taster:

Atomic Structure - Chapter 2 Nancy Dirar…read more

Page 5

Preview of page 5

Here's a taster:

Atomic Structure - Chapter 2 Nancy Dirar
Beta emissions
Beta emissions involve emission of electrons, common among lighter elements with relatively large
number of neutrons.
Relative Charge -1
Relative Mass 0.00055
Nature High kinetic energy electrons produced by changing
protons
Range in Air Few metres
Stopped By Aluminium foil as it has moderate penetration due to
its 'middle' values of charge and mass.…read more

Page 6

Preview of page 6

Here's a taster:

Atomic Structure - Chapter 2 Nancy Dirar
Involves the emission of energy from the nucleus changing from a high energy level to a lower one
often accompanied by alpha and beta decay.
Relative Charge 0
Relative Mass 0
Nature High frequency EM radiation
Range in Air Very long distances
Stopped By Lead Sheet due to smallest mass and
charge causing it to be very penetrating.…read more

Page 7

Preview of page 7

Here's a taster:

Atomic Structure - Chapter 2 Nancy Dirar
Radioactive Half Life
This is the time for half to nuclei to decay.
It is a fixed time for any isotope and unaffected by amount of isotope present, chemical
form, temperature or present.
In one half-life half the radioactivity of the same disappears.
A graph demonstration half-life.…read more

Page 8

Preview of page 8

Here's a taster:

Atomic Structure - Chapter 2 Nancy Dirar
The uses of radioactivity
The dangers of emissions
All radioactive emission is dangerous to living organisms due to its ionisation effects.
Can kill cells, cause genetic damage or burn effects.
Inside the body the 'danger' order is alpha > beta > gamma. The bigger the mass or charge of
the particle, the bigger its ionising impact on atoms or molecule.…read more

Page 9

Preview of page 9

Here's a taster:

Atomic Structure - Chapter 2 Nancy Dirar
2) Must have been no movement of either parent or daughter isotope out or into a mineral since
time of crystallisation.
3) Must be no resetting of radioactive clock. Metamorphism (heating and deforming rocks) can cause
this which can cause reposition or loss of radioisotopes.
Use of radioisotopes in archaeology
- Carbon 14 occurs naturally among carbon 12 in living things.
- The ratio of these carbon isotopes does not change whilst the organism is alive.…read more

Page 10

Preview of page 10

Here's a taster:

Atomic Structure - Chapter 2 Nancy Dirar
3) Nuclei of hydrogen atoms in gas cloud join by fusion to create helium,
4) This releases high amounts of energy causing gas cloud to glow causing dense gas cloud to
become a star.…read more

Comments

lola

amazing. do you have it for anymore chem chapters.

10/5 stars all the way XD !!

Similar Chemistry resources:

See all Chemistry resources »See all resources »