In nature, the chlorine atom has two isotopic forms, 35Cl and 37Cl. The masses of each form are 34.96885amu (75.76%) and 36.9659amu (24.24%), respectively. The average mass of a chlorine atom is .

Explanation:

mass avg = ( abundance 1 x mass 1 = abundance  2 x mass 2 )

                = (  75.76% x   34.96885  +  24.24%    x  36.9659)

                = (  0.7576 x34.96885   +   0.2424 x 36.9659  )

                    =  ( 26.49241  +     8.960534  )

                        = 35.45294 amu

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.