How many electrons in an atom could have these sets of quantum numbers n=7 l=3 ml=-1?

Solution:

Since we have ml=-1

it shows that it has two 2e- i;e it fond in 2nd subshell in f orbital. And each subshell can hold 2 e-.

Thus the required answer is 2 electrons hold by an atom.

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.