Topic 1 - Water and Life

What does it mean that water is a polar molecule?

its electrons are not shared equally, giving it a slight negative charge on the oxygen end and a slight positive charge on the hydrogen ends

What is a polar molecule?

Molecule has a positive and a negative end because electrons are shared unevenly

Why is water a polar molecule?

It’s bent shape and the high electronegativity of the oxygen atom cause uneven electron sharing

What are hydrogen bonds?

Attraction between a positive hydrogen atom and a negative atom. Polar covalent bond

What do hydrogen bonds have to with the properties of water?

Create a sticky network that gives water unique properties: high boiling point, heat capacity, surface tension, cohesion/adhesion

What is specific heat capacity?

heat needed to raise a substance’s temperature

What is heat of vaporization?

energy to change a substance from liquid to gas at constant temperature

How is water compared to other substances?

extremely cohesive and a transporter of nutrients

What is cohesion?

attraction between like molecules

What is adhesion?

attraction between unlike molecules

What is surface tension?

property of a liquids surface to behave like a stretched elastic membrane. Cohesion force pulls liquid’s surface molecules closer minimizing surface area allowing things to float

What is transpiration? What environmental factors that influence it?

process where plants release water vapor into the air through stomata leaves for water/nutrient transporting and cooling influenced by light, temperature, humidity, and wind