Answer:
1. Conductors (Yes) : Li, Ca, Mg, Mn, V, Sc, Y, Na, K
a) Energy level 2 = Li
b) Energy level 3: Na, Mg
b. (i) One valence electron = Na
b. (ii) Two valence electrons = Mg
2. Conductors (No) : Br, I, S, As, Sb
a) Energy level 3 = S
b) Energy level 4: Br, As
b. (i) Seven valence electrons = Br
b. (ii)Five valence electrons = As
Explanation:
Conductors are elements which are able to conduct heat and electricity easily. They are usually metallic elements.
From the list of elements, the metals are: Li, Ca, Mg, Mn, V, Sc, Y, Na, K.
From the list of conductors, Li alone has the energy level of 2.
Na and Mg both have energy level of 3 but Na has one valence electron while Mg has two.
Non-conductors or poor conductors do not allow either heat or electricity to pass through them easily. They are usually the non-metals and semimetals or metalloids.
From the list of elements, the poor conductors are: Br, I, S, As, Sb
Only the element S, has an energy level of 3. Both Br and As have energy levels of 4 each. However, Br has seven valence electrons while As has five valence electrons.
The elements identified can be used to fill the dichotomous key attached below.
