Which element is a p-block metal?
Correct Answer: \( \boxed{\mathrm{A}} \)
The p-block contains elements whose differentiating electron enters a p-orbital.
Tin, \( \mathrm{Sn} \), is a metal in Group 14 and belongs to the p-block. Its outer electron configuration is:
\( \mathrm{[Kr]\,4d^{10}5s^25p^2} \)
Tellurium and astatine are p-block elements but are classified as non-metals or metalloids, while cadmium is a d-block metal.
Therefore, the correct answer is (A).
Which oxide is the most basic?
Correct Answer: \( \boxed{\mathrm{A}} \)
Across Period 3, the oxides generally become less basic and more acidic from left to right.
\( \mathrm{MgO} \) is a basic ionic oxide and reacts with acids to form a salt and water:
\( \mathrm{MgO+2HCl\rightarrow MgCl_2+H_2O} \)
\( \mathrm{Al_2O_3} \) is amphoteric, \( \mathrm{SiO_2} \) is acidic, and \( \mathrm{SO_3} \) is strongly acidic.
Therefore, the most basic oxide is \( \mathrm{MgO} \), so the correct answer is (A).
Correct answer: B
• The spectrum shows only one singlet → all protons must be chemically equivalent.
• CH₃COOCH₃ has two equivalent methyl groups giving a single peak around 2 ppm.
• The other molecules have multiple proton environments → multiple signals, not one.
