If the boron nitride molecule, bn, were to form, what would its structure look like? add bonds and lone pairs as necessary.

The structure for the boron nitride molecule will be linear.

Explanation: When boron and nitrogen combine together to form a compound, the boron element will loose 3 electrons which will be easily accepted by the nitrogen element.

Boron : Atomic number is 5

Electronic configuration:

To attain stable configuration, boron will loose 3 electrons easily.

Nitrogen : Atomic number is 7

Electronic configuration:

To attain stable configuration. nitrogen will gain 3 electrons easily.

Hence, to form a molecule with these two elements, there will be 3 bonds present in between them and 1 pair of lone pair will be left on the nitrogen atom.

Structure of boron nitride ( which is linear) is attached in the image below.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.