Frost and Plant Physiology Quiz

What is frost a result of?

• Water vapor in the air freezing at temperatures above 0 °C (32 °F)

• Water vapor in the air depositing on a surface when the outside temperature drops below 0 °C (32 °F)

• Snowflakes melting and refreezing on plant surfaces

• Ice forming directly from gaseous water without going through the liquid phase

What is the term used to describe the phase change from a gas to a solid without going through the liquid phase?

• Sublimation

• Deposition

• Condensation

• Freezing

At what temperature can a few minutes of exposure result in plant death?

• Below 0 °C (32 °F)

• Below -0.6 °C (31 °F)

• Below -2 °C (28 °F)

• Below -5 °C (23 °F)

What is the primary water phase within plant cells at the cellular level?

• Solid

• Liquid

• Gas

• Plasma

What was the purpose of using ice to protect crops against frost damage according to the research in Washington State in 1920?

• To cool down the plants to match the outside temperature

• To provide water for the plants during a drought

• To ensure that the temperature remains at 0 °C (32 °F) until the freezing process is complete

• To insulate the plants from the cold temperatures

What is the connection between phase changes and energy?

• Energy is always absorbed during phase changes

• Energy is always released during phase changes

• Energy can be either absorbed or released during phase changes

• There is no connection between phase changes and energy

What type of intermolecular force is responsible for the attraction between water molecules?

• Intramolecular forces

• Covalent bonds

• Ionic bonds

• Intermolecular forces

What are the hydrogen bonds in water also referred to as?

• H-bonds

• Covalent bonds

• Ionic bonds

• Van der Waals forces

What happens to the H-bonds between water molecules when water changes from solid to liquid?

• They become stronger

• They remain unchanged

• Some of them are broken

• They turn into covalent bonds

What is the term used to describe the heat of fusion when water freezes?

• Heat of vaporization

• Heat of sublimation

• Heat of condensation

• Heat of freezing