Question

question 3. element x reacts with copper to form the compounds cux and cux₂. in which group on the periodic table is element x found?

○ group 1

○ group 2

○ group 13

○ group 17

Explanation:

Step1: Analyze Copper's Oxidation States

Copper can have oxidation states of +1 (in \( \text{CuX} \)) and +2 (in \( \text{CuX}_2 \)). Let the oxidation state of \( \text{X} \) be \( n \). For \( \text{CuX} \) (Cu is +1), using the rule that the sum of oxidation states in a compound is zero: \( +1 + n = 0 \Rightarrow n = -1 \). For \( \text{CuX}_2 \) (Cu is +2): \( +2 + 2n = 0 \Rightarrow n = -1 \). So \( \text{X} \) has an oxidation state of -1, meaning it gains one electron to achieve a stable octet, characteristic of halogens.

Step2: Relate to Periodic Table Groups

Halogens are found in Group 17 of the Periodic Table. Group 1 elements (alkali metals) have a +1 oxidation state, Group 2 (alkaline earth metals) have +2, and Group 13 have +3 (or -5 in some cases, but not -1). So \( \text{X} \) must be in Group 17.

Answer:

Group 17