The molecule of water is described as a polar molecule. Polar molecules have an unequal sharing of electrons. Explain how this unequal sharing is present by using our water molecule graphic below.
Water is an excellent solvent. With water being a polar molecule, it can be an especially strong solvent for other polar molecules. Give an example of how water acting as a solvent is important for living organisms.
The below picture shows water's ability for adhesion and cohesion. Define adhesion and cohesion and explain why they are important for the plant in the graphic below.
Describe the property of water being shown below. How do water's hydrogen bonds contribute to this property?
The graphic below shows a water molecule with two hydrogen atoms and one oxygen atom. The oxygen atom is larger and has a stronger pull on the shared electrons compared to the hydrogen atoms. As a result, the oxygen atom becomes slightly negative (δ-) and the hydrogen atoms become slightly positive (δ+). This unequal sharing of electrons creates a polarity within the molecule, making it a polar molecule.
Example: Water acting as a solvent is important for living organisms because many biological molecules, such as proteins and nucleic acids, are polar or charged. Water's polarity allows it to surround and dissolve these molecules by forming hydrogen bonds with them, effectively breaking them apart and allowing for various biochemical reactions to occur.
Adhesion refers to the ability of water to stick to other substances, while cohesion refers to the ability of water molecules to stick to each other. In the plant graphic, adhesion allows water molecules to stick to the cell walls of the plant, helping the water to move upward against gravity through the xylem vessels. Cohesion, on the other hand, enables water molecules to stick together, forming a continuous column or stream of water in the plant's xylem vessels. These properties of adhesion and cohesion are essential in enabling plants to transport water and nutrients from the roots to the rest of the plant.
The property shown in the graphic is surface tension. Surface tension refers to the cohesive force between water molecules at the surface, causing the surface of water to behave as if it has a thin "skin." This property is due to the hydrogen bonds between water molecules, which create a strong attraction between them. These hydrogen bonds contribute to surface tension by causing the water molecules at the surface to pull together, reducing the surface area and minimizing contact with the air.