- Types and Nature of Radiation
- Half-life as a measure of the stability of the nucleus.
This is the spontaneous emission of radiation by radioactive element such as Thorium, Uranium etc.
- Spontaneously and continually emitting of radiation by radioactive element
- Temperature and pressure have no effect on radioactivity
- The radiation can pass through opaque objects
- It affects photographic plates
- It causes ionization of gases through which it passes.
- It causes fluorescence of certain substance
- It releases large amount of energy.
Types of Radiation
There are three (3) types of radiation
Characteristics of Alpha-Rays
- they are helium in nature 42He with 4 atomic mass and 2 atomic number
- alpha rays are fast moving streams of positively charges
- they are deflected toward the negative plate in an electrostatic field
- they have very low penetrating power
- they can be absorbed/stopped by a thin sheet of paper on aluminium foil
- they cause fluorescence of some materials e.g zinc sulphide
Characteristics of Beta-rays
- they are electron in nature with a mass number of zero and charge of -1 (oe)
- they are fast moving stream of electrons
- they can penetrate than alpha rays
Effects of Electrostatic Field on the Three Radiation
- State two (2) properties of ά, β, and Y rays each.
- What do you know about radioactivity.
Detection of Radiation
The radiation can be detected by using the following devices.
- Geiger Miller Counts
- Scintillation counter
- Diffusion cloud chamber
The half-life of a radioactive element is the time taken for half of the actual number of atoms in a given substance or radioactive element to decay.
The spontaneous disintegration/decay of nucleus of an element is due to its instability.
The neutron-proton ration determines the stability of an element.
This varies between unity for the lighter elements and a value of about 1.5 for the heavier element with atomic numbers around eighty.
N.B. Atoms with a neutron – protons less than 1 or greater than 1.5 tends to be unstable.
- State two methods through which a radiation can be detected.
- What is half life as a measure of the stability of the nucleus
- Define the term nuclear chemistry
- Define the term radioactivity.
- Explain the term radioisotopes
- Give an account of the uses of radioisotopes.
New School Chemistry by O.Y, Ababio pages 299-304.
- ____ is an example of radiation (a) Aloha (b) Carbon (c) Uranium (d) Nucleus.
- Alpha particle was deflected towards negative plate while Beta deflected toward (a) Neutral plate (b) Negative plate (c) Zero plate (d) positive plate
- The following caused fluorescence of matter except (a) Alpha (b) Beta (c) Gamma (d) X- ray
- In the above diagram, Z represents (a) Alpha (b) Beta (c) Gamma (d) Radioactive
- B represents ____ in the diagram above (a) Alpha (b) Beta (c) Gamma (d) Radioactive source
- Find the half-life of a radio isotope element which was found to be 120g initially and later changed to 15g in 24 hours
- State the three main type of radiation with their properties each.