Which statement is true about water molecules? a. The oxygen atom has a negative charge. b. The hydrogen atoms do not share electrons. c. Water molecules move randomly around each other. d. Water molecules cannot dissolve many substances. How does water relate to the ability of a living thing to generate energy? a. Water is responsible for the generation of energy in the cell. b. The cell is an aqueous environment. c. Without the proper balance of water, chemical reactions in cells could not take place. What is the most important role of hydrogen bonding between water molecules? a. It enables water molecules to bond to each other. b. It allows oxygen and hydrogen atoms to be charged. c. It allows cells to keep water in balance.
The Correct Answer and Explanation is:
- Which statement is true about water molecules?
- Correct Answer: a. The oxygen atom has a negative charge.
- Explanation: Water molecules are polar, meaning there is an uneven distribution of charge. Oxygen is more electronegative than hydrogen, so it attracts the shared electrons more strongly. As a result, the oxygen atom carries a partial negative charge, and the hydrogen atoms carry partial positive charges. This polarity is essential for many of water’s unique properties, like its ability to dissolve many substances.
- How does water relate to the ability of a living thing to generate energy?
- Correct Answer: c. Without the proper balance of water, chemical reactions in cells could not take place.
- Explanation: Water is crucial in living organisms because it facilitates many biochemical reactions, including those involved in energy production. It acts as a solvent for enzymes and other molecules needed for metabolic processes. Additionally, water is involved in processes like cellular respiration, where energy is produced. Without the correct balance of water, cells cannot function properly, and energy production would be impaired.
- What is the most important role of hydrogen bonding between water molecules?
- Correct Answer: a. It enables water molecules to bond to each other.
- Explanation: Hydrogen bonding is the attraction between the partially positive hydrogen atoms of one water molecule and the partially negative oxygen atoms of another. This bonding is responsible for water’s high surface tension and cohesion. Cohesion allows water molecules to stick together, which is important for processes like water transport in plants and the formation of water droplets. The ability to bond with each other also contributes to water’s high boiling point and its ability to moderate temperature changes.
