Final answer:
The correct electron configuration for zinc (Zn) is [Ar]4s^23d^10 (option A), and for technetium (Tc), it is [Kr]5s^24d^5 (option B), both in noble-gas notation.
Step-by-step explanation:
Using the periodic table, we can determine the electron configurations for zinc (Zn) and technetium (Tc) using noble-gas notation.
For zinc (Zn), which has an atomic number of 30, the electron configuration up to argon (previous noble gas) is written as [Ar], and beyond argon, zinc has 4s2 and 3d10. Therefore, the correct electron configuration for zinc in noble-gas notation is [Ar]4s23d10, which corresponds to option A).
For technetium (Tc), the element with an atomic number of 43, the nearest previous noble gas is krypton (Kr). Beyond krypton, technetium has one electron in 5s and five electrons in 4d. Hence, the noble-gas electron configuration for technetium is [Kr]5s24d5, which aligns with option B).