Answer:
A neutral particle made of an electron and hole
Explanation:
Exciton
It is the combination of an electron and a hole ( hole refers to the vacancy of an electron ) . And , as both the electron and the hole have the same charge but the polarity is opposite , the combination will lead to a neutral compound , i.e. , Exciton have no charge and so neutral .
It is free to move in the nonmetallic crystal and since it charge less , it is difficult to detect it directly .
Answer:
d
Explanation:
because boron and fluorine are both nonmetals and don't fit the guidlelines for creating ionic compounds
Weighs 0.001836 gram per cubic centimeter or 1.836 kilogram per cubic meter
Try to see if this helps
1 significant figure, because there is no decimal after the zero the zero doesn't count.
I'm pretty sure it's 9726 milligrams of iodine. Hope this helps.