1.1.1 Structure of the atom

• Neutrons have a neutral charge.


  True
• Isotopes have the same atomic number but different mass numbers.


  True
• Isotopes have different numbers of neutrons.


  True
• What is the maximum number of electrons the first energy level can hold?

  2
• What does the mass number of an atom represent?

  Protons and neutrons
• Electrons have a negative charge and are relatively light
• Where do protons and neutrons reside in an atom?

  In the nucleus
• What is the charge and approximate mass of a proton?

  +1, 1 amu
• What principle governs the filling of electron energy levels in an atom?

  Lowest energy first
• What is the electronic configuration of hydrogen (H)?

  1s¹
• What is a radioactive isotope of carbon used in carbon dating?

  ¹⁴C
• What is the fundamental building block of all matter?

  The atom
• What is the charge of an electron?

  -1
• Where are protons located in an atom?

  In the nucleus
• Arrange the subatomic particles by their mass from heaviest to lightest:

  1️⃣ Protons

  2️⃣ Neutrons

  3️⃣ Electrons
• The second energy level can hold a maximum of 8
• The atomic number of an element is equal to the number of protons in its nucleus.


  True
• Electrons have a negative charge and a negligible mass
• Arrange the electron energy levels in order of increasing energy:

  1️⃣ 1

  2️⃣ 2

  3️⃣ 3

  4️⃣ 4

  5️⃣ 5
• The electronic configuration of an atom describes the distribution of electrons among its energy levels and orbitals
• Oxygen (O) has the electronic configuration 1s² 2s² 2p⁴.


  True
• Protons have a positive charge of +1
• The atomic number is the number of protons
• Electrons orbit the nucleus in electron shells
• Match the subatomic particle with its charge:

  Protons ↔️ +1

  Neutrons ↔️ 0

  Electrons ↔️ -1
• Electrons fill the lowest energy levels first.


  True
• What are the three primary subatomic particles that make up an atom?

  Protons, neutrons, electrons
• Match the subatomic particle with its charge:

  Protons ↔️ +1

  Neutrons ↔️ 0

  Electrons ↔️ -1
• The mass of a neutron is approximately equal to the mass of a proton.


  True
• The second energy level in an atom can hold a maximum of 8 electrons.


  True
• Match the orbital type with its shape:

  s ↔️ Spherical

  p ↔️ Dumbbell

  d ↔️ Complex
• Isotopes of an element have the same number of protons but different numbers of neutrons