Study Notes
Atoms consist of three sub-atomic particles: protons, neutrons, and electrons, with protons and neutrons located in the nucleus and electrons in shells around it.
- Proton — positively charged subatomic particle found in the nucleus. Example: Hydrogen atoms have one proton.
- Neutron — neutral subatomic particle found in the nucleus. Example: Carbon atoms typically have six neutrons.
- Electron — negatively charged subatomic particle found in shells around the nucleus. Example: Oxygen atoms have eight electrons.
- Nucleus — the central part of an atom containing protons and neutrons. Example: The nucleus of a helium atom contains two protons and two neutrons.
- Electronic Configuration — the arrangement of electrons in an atom's shells. Example: The electronic configuration of magnesium is 2,8,2.
Exam Tips
Key Definitions to Remember
- Proton: Positively charged particle in the nucleus.
- Neutron: Neutral particle in the nucleus.
- Electron: Negatively charged particle in shells around the nucleus.
- Nucleus: Center of the atom containing protons and neutrons.
- Electronic Configuration: Arrangement of electrons in shells.
Common Confusions
- Confusing the charge of protons and electrons.
- Misunderstanding the arrangement of electrons in shells.
Typical Exam Questions
- What is the charge of a proton? Positive (+1)
- How are electrons arranged in an atom? In shells around the nucleus.
- What is the electronic configuration of lithium? 2,1
What Examiners Usually Test
- Understanding of the structure of an atom.
- Ability to describe electronic configurations.
- Knowledge of the historical development of atomic models.