Atoms
- Everything is made of atoms.
- They are the ‘building blocks of matter’.
- Atoms are very small - they have a radius of about 0.1 nanometers.
- They’re made up of a nucleus (which contains protons and neutrons) with electrons orbiting around it.
The definition of an atom is “the smallest part of an element that can exist”.
Subatomic particles
Atoms are made up of 3 types of subatomic particles (the things inside the atom itself):
- proton - positively charged particles found in the nucleus
- neutron - neutral particles found in the nucleus
- electron - negatively charged particles which orbit the nucleus
Models of the atom
There are lots of different ways we can model the atom.
The one that is most commonly used today is the Bohr model, which shows a small nucleus made up of protons and neutrons, with electrons orbiting around it in their own energy levels (called shells).
flashcards
| Question | Answer |
|---|---|
| What is an atom? | The smallest part of an element that can exist. |
| What is the approximate radius of an atom? | About 0.1 nanometers. |
| What are the three subatomic particles? | Protons, neutrons, and electrons. |
| Where are protons found and what is their charge? | In the nucleus; positively charged. |
| Where are neutrons found and what is their charge? | In the nucleus; neutral (no charge). |
| Where are electrons found and what is their charge? | Orbiting the nucleus; negatively charged. |
| What is the most commonly used model of the atom today? | The Bohr model. |
| What does the Bohr model show? | A small nucleus made of protons and neutrons, with electrons orbiting in energy levels called shells. |