Question

1. what is the maximum number of electrons that can occupy a single orbital? a) 1 b) 2 c) 3 d) 4 14. the dual nature of the electron suggests that it behaves both as: a) a wave and a particle b) a proton and a neutron c) a photon and a boson d) a particle and a quark 15. what does it mean when an electron is \in an excited state\? a) the electron is at its lowest possible energy level b) the electron has absorbed energy and moved to a higher energy level c) the electron has been removed from the atom d) the electron has emitted energy 16. what does the quantum mechanical model suggest about the nature of electrons in atoms? a) electrons have fixed orbits b) electrons exist in orbitals, which are probability regions c) electrons revolve around the nucleus like planets around the sun d) electrons can collide with the nucleus 17. in an atom, how many d orbitals are there in a single energy level? a) 1 b) 3 c) 5 d) 7 18. when an electron drops from a higher energy level to a lower one, it: a) absorbs a photon b) emitted a photon c) gains energy d) increases in mass

Explanation:

1. According to the Pauli - exclusion principle, a single orbital can hold a maximum of 2 electrons with opposite spins.
2. The electron has a dual nature, behaving as both a wave and a particle, which is a fundamental concept in quantum mechanics.
3. An electron in an excited state has absorbed energy and moved to a higher energy level.
4. The quantum - mechanical model suggests that electrons exist in orbitals, which are probability regions rather than fixed orbits.
5. In a single energy level, there are 5 d - orbitals.
6. When an electron drops from a higher energy level to a lower one, it emits a photon, as the excess energy is released in the form of electromagnetic radiation.

Answer:

1. B. 2
2. A. A wave and a particle
3. B. The electron has absorbed energy and moved to a higher energy level
4. B. Electrons exist in orbitals, which are probability regions
5. C. 5
6. B. Emitted a photon