A student needs to determine the density of an unknown rock sample by dropping the rock into a graduated cylinder containing water. The original volume in the graduated cylinder is 23.0 ml. The student then drops the rock sample into the graduated cylinder and determines the new volume to be 30.0 ml. If the mass of the rock is determined to be 20.4 grams, what is the density of this sample?

Explanation:

The density of a substance can be found by using the formula

volume = final volume of water - initial volume of water

volume = 30 - 23 = 7 mL

We have

We have the final answer as

Hope this helps you

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.

the answer is barium and copper bromide