Question

question 18 (1 point)
which of the following elements is a transition metal?
o a copper
o b tin
o c cesium
o d tellurium

question 19 (1 point)
which of the following groupings contains only representative elements?
o a ni, fe, zn
o b al, mg, li
o c hg, cr, ag
o d cu, co, cd

question 20 (1 point)
which of the following is true about the electron configurations of the representative elements?
o a the electrons with the highest energy are in a d sublevel.
o b the electrons with the highest energy are in an f sublevel.
o c the highest occupied s and p sublevels are partially filled.
o d the highest occupied s and p sublevels are completely filled.

Explanation:

Question 18

• Copper (\(Cu\)) is in the d - block of the periodic table. Transition metals are in the d - block (groups 3 - 12).
• Tin (\(Sn\)) is a post - transition metal (p - block).
• Cesium (\(Cs\)) is an alkali metal (s - block).
• Tellurium (\(Te\)) is a metalloid (p - block).

• Representative elements are in the s - and p - blocks.
• \(Ni\), \(Fe\), \(Zn\) are transition metals (d - block).
• \(Al\) (group 13), \(Mg\) (group 2), \(Li\) (group 1) are in the s - and p - blocks (representative elements).
• \(Hg\), \(Cr\), \(Ag\) are transition metals (d - block).
• \(Cu\), \(Co\), \(Cd\) are transition metals (d - block).

• Representative elements (s - and p - block elements) have their highest - energy electrons in s or p sublevels.
• For a: Transition metals have highest - energy electrons in d sublevels.
• For b: Inner - transition metals (f - block) have highest - energy electrons in f sublevels.
• For c: Representative elements have their highest - occupied s and p sublevels partially filled (except noble gases which have them completely filled, but noble gases are also considered representative elements in some contexts. However, the general electron - configuration trend for non - noble - gas representative elements is that the highest - occupied s and p sublevels are partially filled).
• For d: This is only true for noble gases among representative elements. But when considering the general electron - configuration of representative elements (excluding noble gases), the highest - occupied s and p sublevels are partially filled.

Answer:

a. copper

Question 19