Ch23 Atoms And radioactivity Flashcards
What is a electron
Negative particle (-1 charge)
Mass is 1/2000 in relation to proton
Found in the shells surrounding the nucleus
What is a proton
Positive particle (pos charge of +1)
Relative mass of 1
In the nucleus
What is a neutron
A neutral particle (0 charge)
Relative mass of 1
Found in the nucleus
What are nucleons
Protons and neutrons in the nucleus of the atom
What is the atomic number
Bottom number
No of protons each atom contains (eg carbon has 6 protons in its nucleus therefore the atomic no of carbon is 6)
What is the atomic mass/nucleons number
Top number on periodic table
Total no of protons and neutrons in the nucleus of atom (doesn’t inc electrons cos they’re so light)
Dependent on whether the element is an isotope or not
What is the nucleon number
Same as atomic mass
How to work out mass number?
Number of neutrons + protons
How to work out number of neutrons?
Mass number - number of protons
What is an isotope
Atoms of the same element with different numbers of neutrons
Mass no will be different to original element but atomic no is the same
What is stability?
Having equal numbers of protons and neutrons in the nucleus
Why are some atoms unstable?
Too many or too few neutrons in the nucleus. It will eventually decay
What happens to an unstable atom?
It’ll eventually decay (it will give out energy and may also give out alpha or beta particles)
What is nuclear force?
The strong force which holds protons in the nucleus
What is electric force?
Opposes the nuclear force: it repels the protons away from each other
