Question

1. what property allows water to form hydrogen bonds? (1 point)

ionic bonds
radioactivity
polarity
isotopes

1. what property of water makes it useful for cooking? (1 point)

ice floats
its wet (or is it?)
it is ionic
it holds its temperature well

1. why does ice float? (1 point)

solid ice is less dense than liquid water
solid ice is more dense than liquid water
ice and liquid water have same density

Explanation:

Question 9

To determine the property allowing water to form hydrogen bonds, we analyze each option:

• Ionic bonds: Water has covalent bonds, not ionic, so this is incorrect.
• Radioactivity: Water isn't radioactive, so this is wrong.
• Polarity: Water is a polar molecule (oxygen is more electronegative than hydrogen, creating partial charges). These partial charges allow hydrogen bonds to form between water molecules (the partially positive H of one molecule is attracted to the partially negative O of another).
• Isotopes: Isotopes are variants of an element, not related to hydrogen bonding in water.

To find the property of water useful for cooking, we evaluate the options:

• Ice floats: This property is relevant to aquatic ecosystems, not cooking, so incorrect.
• Its wet (or is it?): "Wetness" is not a scientific property of water relevant to cooking, and water itself isn't "wet" in the way the option implies (wetness is a perception of a liquid adhering to a surface).
• It is ionic: Water is a covalent compound, not ionic, so this is wrong.
• It holds its temperature well: Water has a high specific heat capacity, meaning it can absorb and retain heat. This makes it useful for cooking (e.g., boiling, simmering) as it can transfer heat to food effectively and maintain a stable temperature.

To explain why ice floats, we consider density:

• Solid ice is less dense than liquid water: When water freezes, the hydrogen bonds form a crystalline structure that spaces the molecules further apart than in liquid water. This lower density means ice is less dense than liquid water, so it floats.
• Solid ice is more dense than liquid water: If this were true, ice would sink, which it doesn't, so incorrect.
• Ice and liquid water have same density: If densities were equal, ice wouldn't float or sink preferentially, but we know ice floats, so this is wrong.

Answer:

C. polarity

Question 10