D IS THE ANSWER TO YOUR QUESTION
Answer:
(BH3 follows the octet rule by dimerizing, as Hadi Kurniawan AR pointed out.) For H and He, an "octet" = 2 electrons. Boron does prefer to follow the octet rule, in that it likes to form borate compounds such as NaBH4. It also is happy to form compounds with elements with lone pairs.
Answer:
Because you can physically see the object melting when it comes to the melting point. The objects texture, color, temperature, shape, and state of matter (solid, liquid, gas) are possibly changing.
1 mole ------------- 22.4 L ( at STP )
?? mole ---------- 12 L
12 x 1 / 22.4 => 0.5357 moles
hope this helps!
