Question

1. true or false: according to the aufbau principle, electrons fill orbitals randomly without regard to energy levels.
2. true or false: hunds rule states that electrons prefer to pair up in degenerate orbitals with opposite spins.
3. true or false: transition metals exhibit irregular filling of d - orbitals, which contradicts the aufbau principle.
4. true or false: the periodic trend in atomic radius across a period is attributed to decreasing nuclear charge.
5. true or false: elements with stable, fully - filled or half - filled subshells tend to have lower ionization energies.
6. true or false: valence electrons play a minor role in determining an elements chemical reactivity.
7. true or false: elements in the halogen group share similar electronic configurations and tend to form cations.
8. true or false: the stability of an atoms electronic configuration is enhanced by increasing the number of unpaired electrons.
9. true or false: hunds rule emphasizes the preference of electrons to occupy degenerate orbitals singly before pairing up.
10. true or false: the interplay between electronic configuration and periodicity forms the basis for understanding chemical bonding.

Explanation:

1. The Aufbau Principle states electrons fill orbitals from lowest to highest energy.
2. Hund's Rule says electrons occupy degenerate orbitals singly first.
3. Transition metals' d - orbital filling (e.g., Cr, Cu) seems irregular but is due to stability (half - filled/filled).
4. Atomic radius across a period decreases as nuclear charge increases (more protons attract electrons).
5. Stable subshells (fully - filled/half - filled) have higher ionization energies (harder to remove electrons).
6. Valence electrons are crucial for chemical reactivity (involved in bonding).
7. Halogens form anions (gain electrons to achieve noble gas configuration).
8. Stability is from electron configuration (not just number of unpaired electrons).
9. Hund's Rule is about single occupancy before pairing.
10. Electronic configuration and periodicity are fundamental to chemical bonding (e.g., valence electrons determine bonding type).

Answer:

1. False
2. False
3. False
4. False
5. False
6. False
7. False
8. False
9. True
10. True