Science Unit 3 - Notes #2
Water freezes at _ ° Celsius.
0
Density: _ gram per cubic centimeter
1
Water boils at _ ° Celsius.
100
What percentage of earth is made of water?
71%
Non-polar substances _________ with water.
Do not mix
Give an example of cohesion
Droplets of dew on grass
Define cohesion in your own words.
Holds water molecules together, causes it to stick to each other
Define adhesion in your own words.
Holds water to a surface
Why do humans sweat and dog pant? Explain the purpose and the reason both are effective.
Humans sweat because we have skin and it cools us down. Dogs pant because they have fur. This it effective because it helps regulate body temperature.
Water's unique properties are due to ______________
Hydrogen bonding
What causes surface tension in water?
Hydrogen bonds cause the molecules to stick to each other on top of the water.
High Specific Heat
Hydrogen bonds release heat when they break and form. It takes a lot of energy to heat water, freeze water and melt ice.
Water on earth is found in
Ice caps, freshwater lakes, salt lakes, rivers, ocean, underground, and atmosphere.
Give an example of surface tension
Insects can walk on water
Water has unique properties because of.....
It's positive and negative ends and it is polar
Chromatography
Method used to separate complex mixtures using capillary action.
Polar substances ___ with water.
Mix
Meniscus
The curved surface at the top of a column of liquid caused by adhesion.
How does water get to the leaves in the tops of the tallest trees against the force of gravity. Explain how this property works.
This happens because of capillary action. This is when water can climb up plants by cohesion and adhesion working together.
Two hydrogen atoms, one oxygen
Water
Because water has a high specific heat.....
Water stabilized the temperature of the earth.
Give an example of adhesion.
Water sticks to glass after it is washed.
Why does ice float on water?
ice floats because it is less dense and the molecules are farther apart.
