Atom Structure Quiz Notes

Atom Structure Overview

• Atomic Components:

  • Protons: 1 amu, charge 1+, located in the nucleus.

  • Neutrons: 1 amu, charge 0, located in the nucleus.

  • Electrons: 0 amu, charge 1-, located in shells/clouds.

Key Definitions

• Atomic Number: Number of protons; defines the element and remains constant.

• Atomic Mass: Total number of protons + neutrons; can vary for isotopes.

• Average Atomic Mass: Found on the periodic table; average mass of all isotopes weighted by abundance, usually expressed as a decimal and rounded to the nearest whole number,

Charge Calculations

• Total Charge: Difference between number of protons and electrons.

  • Positive if protons > electrons.

  • Negative if protons < electrons.

  • Neutral if protons = electrons.

• Charge Formula: Total charge = Proton # - Electron #

  • Example: 10 protons & 8 electrons → 10 - 8 = 2+

  • Example: 12 protons & 15 electrons → 12 - 15 = 3-