Question

Which of the following describes the element Kr? Choose all that apply. (A) belongs to a group consisting entirely of gases forms a basic solution in water. (B) is very reactive as a metal. (C) is one of the group of the least reactive elements. (D) reacts vigorously with alkali metals to form salts. (E) consists of diatomic molecules in elemental form.

Answer 1

Answer:

The correct answer is option C.

Explanation:

Kr is the symbol of a noble gas named krypton.It belongs to the group 18 of the periodic table in which all the elements are less reactive.

These noble gases are highly inert and less reactive due to:

• Completely filled $ns^2np^6$ electronic configuration in their valence shell.
• High ionization enthalpies.
• Positive value of electron gain enthalpy.