Water

• How does oxygen's higher electronegativity affect water?

  Oxygen's higher electronegativity attracts electrons more strongly, forming a slightly negative charge (δ–).
• How does surface tension of water affect small organisms like water striders?

  The high surface tension of water allows small insects like water striders to move along its surface by distributing their weight and trapping air with microscopic hairs on their legs.
• How do the physical properties of water influence the adaptations of terrestrial and aquatic organisms?

  The different physical properties of water and air influence the behaviors and adaptations of organisms, such as the black-throated loon and the ringed seal in the Arctic.
• What are hydrogen bonds and their significance in water?

  Hydrogen bonds are inter-molecular associations formed in water due to polar covalent bonds, where a δ+ hydrogen atom is attracted to a δ– fluorine, oxygen, or nitrogen atom, and they are responsible for several unique properties of water.
• How does the polarity of water enable it to interact with other molecules?

  The polarity of water allows it to form weak associations with other polar molecules or charged ions, where the slightly negative poles (δ–) attract the slightly positive poles (δ+) of other molecules, and vice versa.
• How do the physical properties of water contribute to it being the medium of life?

  The physical properties of water, including buoyancy, viscosity, thermal conductivity, and specific heat capacity, sustain living processes and influence the adaptations of organisms.
• Why does hydrogen exhibit a weaker attraction towards electrons in water?

  Hydrogen's weaker attraction towards electrons results in a slightly positive charge (δ+).
• What does it mean for water to be cohesive?

  Water is cohesive, meaning it can stick to other water molecules via the formation of hydrogen bonds, resist low levels of external force (creating surface tension), and be sufficiently dense for certain organisms to move along its surface.
• What role does water play in the transport of substances in plants and animals?

  Water is involved in the transport of water-soluble substances in plants via xylem and phloem, and in animals via blood plasma and specialized lipid transport mechanisms.
• What are the unique adaptations of the ringed seal for its aquatic lifestyle?

  The ringed seal has denser bones for diving, a streamlined body for propulsion, and features like fur and blubber for insulation and waterproofing.
• How does buoyancy work in water and its effect on objects?

  Buoyancy is the upward force applied to an object in a medium, and water's greater density than air results in a greater upward force, allowing objects to float based on their relative weight.
• What is meant by the polarity of water?

  Polarity in water refers to the slight difference in charge that occurs at the different poles of the water molecule.
• How are the hydrogen and oxygen atoms bonded in a water molecule?

  Two hydrogen atoms are covalently bonded to an oxygen atom in a water molecule.
• How does water's properties as a solvent and metabolic medium affect biological processes?

  Water's ability to dissolve a variety of substances makes it an important medium for metabolic reactions, promoting enzyme activity, and affecting the behavior of hydrophilic and hydrophobic substances.
• What is viscosity and how does it apply to water?

  Viscosity is a measure of a fluid’s tendency to flow, and water is more viscous than air due to its ability to form hydrogen bonds and dissolve solutes, which increase the friction of flowing molecules.
• How does capillary action work in plants?

  Capillary action in plants, driven by a pressure gradient created from transpiration and osmosis, allows water to be transported up the stem via narrow xylem vessels and through the soil from the water table.
• What are the unique adaptations of the black-throated loon for its aquatic lifestyle?

  The black-throated loon has less dense bones for buoyancy, non-hollow bones for diving, and specialized feathers for insulation and protection against water.
• Why is water called the universal solvent?

  Water is called the universal solvent because it can dissolve a large number of substances due to its capacity to form dispersive hydration shells with charged particles or electronegative atoms.
• What is solvation and how does it relate to solubility?

  Solvation is the process by which solvent molecules surround and interact with solute molecules to form a solution, and solutes that can be dissolved by a solvent are considered soluble.
• What is specific heat capacity and why is water's specific heat capacity important?

  Specific heat capacity describes the amount of energy required to raise the temperature of a substance, and water has a higher specific heat capacity than air, making it an effective coolant and heat regulator in biological systems.
• What is thermal conductivity and how does water compare to air in this aspect?

  Thermal conductivity is a measure of a substance's ability to move heat across a temperature gradient, and water absorbs and transfers heat more readily than air due to its higher density and tighter particle packing.
• What is meant by the adhesive property of water?

  The adhesive property of water refers to its ability to stick to other polar or charged molecules via the formation of polar associations, and to flow in opposition to gravitational forces (capillary action) by attracting to charged or polar surfaces.