Discover the structure of an atom — protons, neutrons, and electrons — and how they're arranged.
An atom has a nucleus containing protons (positive charge) and neutrons (no charge), with electrons (negative charge) orbiting around it.
Which subatomic particle has a negative charge?
The electron
Where are protons and neutrons located in an atom?
In the nucleus, at the center of the atom
What is the overall charge of an atom, given it has equal protons and electrons?
Neutral, since the positive charge of protons and negative charge of electrons cancel out
The atomic number equals the number of protons. The mass number equals protons plus neutrons.
An atom has 6 protons and 6 neutrons. Find its atomic number and mass number.
Atomic number=6; mass number=6+6=12
Why does the atomic number define which element an atom is?
Because the number of protons determines the element's identity — changing the proton count creates a different element entirely
An atom has 7 protons and 7 neutrons. Find its atomic number and mass number.
Atomic number=7; mass number=7+7=14
1. Name the three subatomic particles.
2. Which particle has a positive charge?
3. An atom has 8 protons and 8 neutrons. Find its mass number.
4. What is the atomic number of an element with 11 protons?
5. Where do electrons move in an atom?
6. Which subatomic particle has no charge?
7. Which subatomic particle has a negative charge?
8. An atom has 12 protons and 12 neutrons. Find its mass number.
9. What is the atomic number of an element with 15 protons?
10. Why does an atom have no overall charge under normal conditions?