Subatomic Particles and Isotopes Quiz

Subatomic Particle Properties

• Atoms are composed of three main subatomic particles: protons, neutrons, and electrons.
• Protons carry a positive charge (+1).
• Neutrons are neutral (charge = 0).
• Electrons carry a negative charge (-1).
• Protons and neutrons reside within the atom's nucleus.
• Electrons orbit the nucleus.

Identifying Isotopes and Ions

• Isotopes: Atoms of the same element with the same number of protons but different numbers of neutrons.
• Ions: Atoms that have lost or gained electrons, resulting in a net positive or negative charge.
• Atomic number: The number of protons in an atom. This uniquely identifies an element.
• Mass number: The sum of protons and neutrons in an atom.
• Number of electrons: For a neutral atom, the number of electrons equals the number of protons. For an ion, it's different.

Nuclear Symbols

• Nuclear symbols represent isotopes and ions concisely. The format generally shows the element symbol, mass number, and atomic number. (e.g., $^{A}_{Z}$X, where X is the element symbol).
  • Top number (A) = mass number
  • Bottom number (Z) = atomic number

Forces in Atoms

• Strong nuclear force: Holds protons and neutrons together in the nucleus overcoming the electrostatic repulsion between positively charged protons.
• Electromagnetic force: Attracts electrons to the positively charged nucleus.

Mass Relationships

• Mass of an atom (approximately): The total mass of the atom is approximately equal to the combined masses of its protons, neutrons, and electrons. Electron mass is typically negligible compared to proton and neutron mass.

Average Atomic Mass

• The average atomic mass of an element is a weighted average of the masses of its isotopes, considering their relative abundances.

Converting Between Atoms, Moles, and Grams

• Mole: A unit that represents 6.022 x 10²³ particles (atoms, molecules, etc.). This is known as Avogadro's number.
• Calculating between atoms, moles and mass uses molar mass and Avogadro's number.