Question

How is the properties of water activity an example of how water molecules behave?

Answer 1

Cohesiveness also leads to high surface tension. An example of the surface tension is seen by beading of water on surfaces and by the ability of insects to walk on liquid water without sinking. Adhesion is another property of water. Adhesiveness is a measure of water's ability to attract other types of molecules.

Answer 2

Water is made of one hydrogen and two oxygen atoms. Water is a non-polar molecule. A non polar molecule is a molecule that has electrons that are shared equally within it, and in this case the hydrogen has a slightly positive charge and oxygen has a slightly negative charge, so they are attracted to eachother and are shared equally, because positives and negatives attract.
This attraction forms someone called hydrogen bonds. This means the water molecules are attracted to eachother and stick to eachother. Hydrogen bonds make water very cohesive. Have you ever filled a glass of water to the very top and then slowly added a few more drops? Before it overflows, the water forms a dome-like shape above the rim of the glass. This dome-like shape forms due to the water molecules’ cohesive properties. Cohesion is the attaction between the same types of molecule ex. Water to water. Waters cohesive properties allows for water to create surface tension, meaning if there is tension put on the water, like if we put something on the surface like a piece of water, it will resist rupturing, that's why is can hold items on its surface. So this is because of waters ability to stick to eachother/ be cohesive. But water prefers actually to stick to other molecules. When a molecule is attracted/sticks to another molecule this is called adhesion. For example, water likes to stick to the side of a glass, for example a test tube,and the adhesion of the water allows it to climb upwards, and this is called capillary action.

Additionally, Water attracts polar molecules as well, basically meaning that the polar molecules would dissolve in water. Sugar is a polar molecule and mixes and dissolves in water, along with nucleic acids and some amino acids. You can call all these polar substances (sugar, nucleics acids etc.) HYDROPHILIC because they dissolve in water. All the substances that don't dissolve in water you can call HYDROPHOBIC. Oil is hydrophobic for example, and it sepates from water.

I think that’s all you need to know, let me know if you have questions.