Subatomic Particles
Chemistry: Edexcel IGCSE, topic 3.1.3
The Charges and Masses of Subatomic Particles
The 3 different sub-atomic particles (protons, neutrons and electrons) have different relative charges. In an atom, these charges all cancel each other out., meaning that atoms have zero overall charge (are neutral).
Protons
- Protons have a relative charge of +1.
- They are found in the nucleus.
- An element’s atomic number is the number of protons it possesses.
- All atoms of the same element will have an identical number of protons.
- Protons have a relative atomic mass of 1.
Electrons
- Electrons have a relative charge of -1.
- Electrons are found in fixed orbits around the nucleus.
- In any atom, the total number of negative electrons equals the number of positive protons, meaning atoms have no overall electric charge.
- Electrons have a relative atomic mass of 1/2000 which we approximate to be 0.
Neutrons
- Neutrons have a relative charge of 0 - they are neutral.
- Like protons, they are found in the nucleus.
- Neutrons have a relative atomic mass of 1.
Test yourself on Subatomic Particles
Sub-atomic particles
Which of the following are true?
What is the overall charge of the nucleus of an atom?