Which element can combine with metals but also readily combines with non-metals very similarly to the way the alkali metals combine?

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

What can be added to the examples section of each circle? endothermic: ice melting into water, and a heat pack becoming warm exothermic: a glow stick glowing, and fireworks exploding endothermic: ice melting into water, and an instant ice pack turning cold exothermic: fireworks exploding, and gasoline burning endothermic: a glow stick glowing, and a heat pack becoming warm exothermic: an instant ice pack turning cold, and ice melting into water endothermic: gasoline burning, and an instant ice pack turning cold exothermic: ice melting into water, and an instant ice pack turning cold

Draw the skeletal structures of two different molecules that are each made of 5 carbon atoms and 12 hydrogen atoms.