1.5 Atomic Structure and Electron Configuration

• Where are protons located within an atom?

  In the nucleus
• What is the key feature of the Bohr model?

  Quantized energy levels
• Atomic spectra are produced when electrons transition between energy levels.
• Atomic structure refers to the internal composition and organization of an atom
• What are the three fundamental subatomic particles?

  Protons, neutrons, electrons
• What is the central concept of the Bohr model?

  Discrete energy levels
• The Bohr model accurately describes the behavior of all atoms.

  False
• The principal quantum number determines the energy level
• The Pauli Exclusion Principle states that no two electrons in the same atom can have the same set of quantum numbers
• The Pauli Exclusion Principle states that no two electrons in the same atom can have the same set of quantum numbers
• What are the quantum numbers for Electron 1 in helium?

  n=1, l=0, ml=0, ms=+1/2
• Where are protons located in an atom?

  In the nucleus
• What does the Bohr model describe about electron orbits in an atom?

  Electrons orbit in discrete energy levels
• Hund's Rule states that electrons will first singly occupy degenerate orbitals with parallel spins before pairing up.


  True
• The Aufbau principle states that electrons fill orbitals from lowest to highest energy.


  True
• When filling degenerate orbitals, Hund's Rule states that electrons occupy each orbital singly before pairing
• What is the condensed electron configuration of Neon (Ne)?

  [Ne]
• What is the electron configuration of Hydrogen (H)?

  1s¹
• The condensed electron configuration of Iron (Fe) is [Ar] 4s² 3d⁶.


  True
• The Pauli Exclusion Principle states that no two electrons can have the same set of quantum numbers.
• The actual electron configuration of Chromium (Cr) is [Ar] 4s¹ 3d⁵ because a half-filled 3d subshell is more stable.


  True
• The sum of protons and neutrons in an atom's nucleus is called its mass number.
• What is the charge of a proton?

  Positive (+1)
• What type of charge do neutrons carry?

  Neutral (0)
• Which subatomic particle has a positive charge?

  Proton
• The atomic number of an element is determined by the number of protons in its nucleus.

  True
• Neutrons have a neutral charge and are located in the nucleus.


  True
• Order the steps involved in energy transitions in the Bohr model:

  1️⃣ Electron absorbs energy

  2️⃣ Electron jumps to a higher energy level

  3️⃣ Electron emits energy

  4️⃣ Electron returns to a lower energy level
• What are the three fundamental particles that make up an atom?

  Protons, neutrons, electrons
• Protons are negatively charged particles.

  False
• Protons and neutrons reside within the nucleus
• When an electron moves to a higher energy level, it absorbs energy
• What are quantum numbers used to describe?

  Electron state in an atom
• What does the magnetic quantum number specify?

  Orbital orientation
• What must two electrons in the same orbital have in common?

  Opposite spins
• Match the quantum number with its description:

  Principal Quantum Number (n) ↔️ Energy level (shell)

  Angular Momentum Quantum Number (l) ↔️ Orbital shape

  Magnetic Quantum Number (ml) ↔️ Spatial orientation

  Spin Quantum Number (ms) ↔️ Electron spin
• The two electrons in helium comply with the Pauli Exclusion Principle because they have different spins.


  True
• Match the subatomic particle with its properties:

  Proton ↔️ +1 charge, in nucleus

  Neutron ↔️ 0 charge, in nucleus

  Electron ↔️ -1 charge, orbits nucleus
• Electrons emit energy when they move to a lower energy level.


  True
• Steps for writing electron configurations according to the Aufbau Principle:

  1️⃣ Fill orbitals from lowest to highest energy

  2️⃣ Follow the Pauli Exclusion Principle

  3️⃣ Apply Hund's Rule