A student finds that an unknown element readily reacts with alkali metals. What is the best conclusion about the unknown element? Just checking my answer

Answer options:

It is in group 17

It is an alkaline earth metal

It is a noble gas

It is in group 16

This element exists in adundance in the sun.explain how you would go about capturing sunlight.would this captured sunlight contain any of the element?

Can someone me with these questions plz.

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line