Lesson 1: Structure of water and hydrogen bonding

Polar molecule

A neutral, or uncharged molecule that has an asymmetric internal distribution of charge, leading to partially positive and partially negative regions

Cohesion

The attraction of molecules for other molecules of the same kind

Adhesion

The attraction of molecules for other molecules of a different kind

Density

The mass per unit volume of a substance

Specific heat capacity

The amount of heat needed to raise the temperature of one gram of a substance by one degree Celsius

Heat of vaporization

The amount of energy needed to change one gram of a liquid substance to a gas at constant temperature

Water polarity

Water molecules are polar, with partial positive charges on the hydrogens and a partial negative charge on the oxygen due to oxygen’s higher electronegativity

Water as a solvent

Water can dissolve many polar and ionic substances, carrying nutrients through the water cycle

High heat capacity

Water requires a lot of energy to raise its temperature, helping regulate environmental temperatures

High heat of vaporization

Water absorbs a large amount of heat when evaporating, which cools organisms through evaporative cooling

Cohesive properties

Water molecules stick to each other via hydrogen bonds, creating surface tension

Adhesive properties

Water molecules stick to other substances, aiding in nutrient transport in plants and other life forms

Ice density

Water is less dense as a solid because ice forms a crystalline structure that spaces molecules farther apart, allowing it to float

Misconception about universal solvent

Water cannot dissolve nonpolar substances like oil because they lack partial charges to attract water molecules