Question

which element is correctly labelled below? element a alkaline earth metal has 12 protons in period 2 low melting point element b metalloid highly reactive has 10 valence electrons brittle element c has properties similar to rb has 1 valence electron has 11 protons good conductor element e noble gas inert (not reactive) has 1 valence electron poor conductor a) element a b) element b c) element c d) element e

Explanation:

Step1: Analyze Element A

Alkaline - earth metals have 2 valence electrons, not 12 protons. Element A is mis - labelled.

Step2: Analyze Element B

Metalloids are not highly reactive like Group 1 or Group 17 elements and usually do not have 10 valence electrons. Element B is mis - labelled.

Step3: Analyze Element C

An element with 11 protons is sodium (Na). Sodium has 1 valence electron, is a good conductor and has similar properties to Rb (both are alkali metals). Element C is correctly labelled.

Step4: Analyze Element D

Noble gases are inert and have a full valence shell (8 electrons except He with 2), not 1 valence electron. Element D is mis - labelled.

Answer:

C. element C