Calculate the number of Aluminium ions present in 1.5 gram of Aluminium oxide

1.771x10^22

Explanation:

6.02x10^23:avogadro's number

2: number of Al ions in Al2O3

1.5/102=0.0147:number of moles in the compound

moles=mass/relative mass number

so 0.0147x(6.02x10^23)x2=1.771x10^22

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.