Answer: The bond between boron and hydrogen in boron trihydride is covalent bond.
Explanation:
The type of bonding between the atoms forming a compound is determined by using the electronegativity difference between the atoms. According to the pauling's electronegativity rule:
- If
, then the bond is non-polar. - If
, then the bond will be covalent. - If
, then the bond will be ionic.
We are given:
Electronegativity for boron = 2.0
Electronegativity for hydrogen = 2.1

As,
is less than 1.7 and not equal to 0. Hence, the bond between boron and hydrogen is covalent bond.
I believe the correct response would be D. At least 2 of the above statements are correct.
Explanation :
The balanced chemical reaction will be,

By the stiochiometry, 3 moles of solid copper(II)oxide react with 2 moles of ammonia gas to give 3 moles of copper metal, 1 mole of nitrogen gas and 3 moles of liquid water.
The states of matter of each elements and compound is,
Copper(II)oxide is in solid state
Ammonia is in gaseous state
Copper metal is in solid state
Nitrogen is in gaseous state
Water is in liquid state
Answer: Ionic substances would be good conductors since they dissolve in water and form ions.
Explanation:
Conductors can be defined as those materials which can allow the electricity to flow through them. The conductors also allow the transmission of heat and light from one to another source. They conduct electricity by allowing the electrons to flow through them easily.
The ionic substances can be good conductors because these can be dissolved in water and they will produce ions. The positively-charged ions will be attracted towards the negative electrode whereas the negatively charged ions to the positive electrode.