P2.5 What happens when radioactive substances decay, and the uses and dangers of their emmisions Flashcards
What is the basic structure of an atom?
A small central nucleus composed of protons and neutrons, surrounded by electrons
What is the relative mass of a proton?
1
What is the relative mass of a neutron?
1
What is the relative mass of an electron?
Very small
What is the relative charge of a proton?
+1
What is the relative charge of a neutron?
0
What is the relative charge of a electron?
-1
In an atom what is the number of electrons equal to?
The number of protons in the nucleus
What is the overall charge of an atom?
0
How do atoms become ions?
They may gain or lose electrons
What is an isotope?
When an atom has a different number of neutrons
Can you have different numbers of protons in an atom?
No it is always the same
What is the atomic number?
The number of protons (and therefore the number of electrons)
What is the mass number?
The total number of protons and neutrons
What do some substances give out from their nuclei all the time?
Radiation
What are substances that give out radiation from their nuclei?
Radioactive
What does background radiation come from?
Natural sources mainly: cosmic rays, rocks and soil, living things. However it can also come from artificial sources such as nuclear weapons and accidents
How many protons and neutrons does an alpha particle have?
2 protons and 2 neutrons
What is a beta particle?
An electron
What is gamma radiation?
A type of electromagnetic radiation
What happens in alpha decay?
The atomic mass number decreases by 4, and the atomic number decreases by 2
What is an example of an equation for alpha decay?
219 215 4
Rn ====> Po + α
86 84 2
What happens in beta decay?
The atomic mass number stays the same, but the atomic number increases by 1
What is an example of an equation for beta decay?
14 14 0
C ====> N + β
6 7 -1
