Question

what characteristic is shared by elements in groups 3-12 (transition metals)?
○ they have 8 valence electrons.
○ they are all gases
○ they are poor conductors of electricity
○ they are less reactive than alkali metals

what is the chemical symbol for antimony? *
○ sn
○ sb
○ a
○ an

what is unique about mercury (hg) among the transition metals?
its the most reactive
cut off text

Explanation:

First Question (Characteristics of Transition Metals - Groups 3 - 12)

• "They have 8 valence electrons" is incorrect; transition metals have variable valence electrons (d - orbital involvement).
• "They are all gases" is wrong; transition metals are typically solids (except mercury, which is liquid).
• "They are poor conductors of electricity" is incorrect; metals (including transition metals) are good conductors.
• "They are less reactive than Alkali Metals" is correct. Alkali metals (Group 1) are highly reactive (e.g., react vigorously with water), while transition metals are generally less reactive.

• Sn is the symbol for Tin.
• Sb is the correct symbol for Antimony (from Latin "Stibium").
• A is the symbol for Aluminum.
• An is not a standard chemical symbol for Antimony.

Most transition metals are solid at room temperature. Mercury (Hg) is unique because it is a liquid at room temperature (and standard pressure). Reactivity - Hg is not the most reactive transition metal (e.g., some like Zn, Fe are more reactive in certain contexts).

Answer:

They are less reactive than Alkali Metals

Second Question (Chemical Symbol for Antimony)