1.1 Atomic Structure

• What is the fundamental unit of matter that makes up all substances?

  Atom
• What does the Bohr model of the atom describe about electron orbits?

  Fixed energy levels
• What is the mass number of an atom?

  Protons and neutrons
• Atoms consist of three main subatomic particles: protons, neutrons, and electrons
• According to the Bohr model, electrons can only exist in certain allowed energy levels
• The atomic number of an atom is the number of protons in its nucleus.
• Isotopes have the same atomic number but different mass numbers.
• How many protons does carbon-12 have?

  6
• Who proposed the Bohr model of the atom?

  Niels Bohr
• The Bohr model describes electrons moving in fixed circular orbits.

  True
• Match the subshell with its maximum number of electrons:

  s ↔️ 2

  p ↔️ 6

  d ↔️ 10

  f ↔️ 14
• The Aufbau principle states that electrons fill the lowest available energy levels
• What are valence electrons and why are they important in chemical bonding?

  Outermost electrons; bonding behavior
• The nucleus of an atom contains protons and neutrons, while electrons orbit the nucleus in shells or energy levels.


  True
• When an electron jumps from a higher energy level to a lower energy level, it releases a photon of light.


  True
• The number of neutrons in an atom can be found by subtracting the atomic number from the mass number.

  True
• What defines isotopes of the same element?

  Same Z, different A
• Isotopes have the same number of protons but a different number of neutrons.


  True
• In the Bohr model, electrons orbit the nucleus in specific energy levels or shells
• What does the atomic number (Z) represent?

  Number of protons
• What are the four types of subshells in the Bohr model of the atom?

  s, p, d, f
• The p subshell is dumbbell-shaped and can hold up to 6 electrons


  True
• The electron configuration of a carbon atom is 1s^2 2s^2 2p^2
• Match the atom with its electron configuration:

  Hydrogen (H) ↔️ 1s^1

  Helium (He) ↔️ 1s^2

  Lithium (Li) ↔️ 1s^2 2s^1

  Beryllium (Be) ↔️ 1s^2 2s^2
• Atoms form chemical bonds to achieve a more stable electron configuration
• What defines isotopes of an element?

  Same atomic number
• The mass number (A) of isotopes differs because they have a different number of neutrons
• Arrange the subatomic particles in order of their mass from heaviest to lightest.

  1️⃣ Protons

  2️⃣ Neutrons

  3️⃣ Electrons
• What is released when an electron jumps from a higher to a lower energy level?

  Photon
• The number of neutrons in an atom can be found using the formula: Mass Number - Atomic Number
• The s subshell has a spherical shape
• In what order do electrons fill the subshells according to the Bohr model?

  s, p, d, f
• What is the purpose of the short hand method for writing electron configurations?

  Simplification and valence electrons
• The number of electrons in each subshell is indicated by the superscript in the electron configuration


  True