Oxygen reacts 1:2 with sodium and is a colourless gas; chlorine reacts 1:1 with sodium and is a yellow gas; neon does not reacts with sodium and is a colourless gas. Suppose that a new element , pretendium, has been dicovered, and it is noted that this element reacts 1:1 with sodium and is bright green as a gas.

A) which chemical family would it belong to?

-I think halogens.

B) How many electrons would it have in its outermost shell?

-7?

1 answer

I agree with halogens.
I don't agree with -7 electrons; I might agree with 7 electrons.