1. Protons, Electrons and Neutrons
What is an Atom?
Protons, Electrons and Neutrons

2. ATOM Smallest particle of any kind of matter
An atom is a million times smaller than the thickest human hair.
The diameter of an atom ranges from about 0.1 to 0.5 nanometers (1 × 10-10 m to 5 × 10-10 m).

3. Subatomic Particles
Inside the atom, there are particles that are even smaller, that make up the atom.
Pieces of the atom, or what the atom is made of.

4. Average Mass Units
Particles in the atom are measured in mass by using Average Mass Units (or amu).
1 kg rice – 1 gram rice – 876 micrograms is the mass of 1 grain of rice
A single amu is *10-27 kg

5. Small, Smaller, Smallest…
Example: 876 micrograms is equal to amu
4) 1 microgram is equal to amu OR
1 amu is equal to *10-21 micrograms

6. PROTONS Positively charged particles with a mass of 1 amu Symbol = p+
Located in the nucleus

7. NEUTRONS Neutral (no charge) particles with a mass of 1 amu Symbol = n
Found also in the nucleus

8. ELECTRONS Negatively charged particles
2000 times smaller than 1 amu (protons and neutrons)
Travel in space around the nucleus (electron shell)

9. Comparing the parts of the atom
How can you use the idea of the track outside like an atom?