Water and Life: Lesson - BWHS

Water on Earth

How Much Water Is on Earth?

Why is the ocean important?

• The ocean covers about 70 percent of Earth’s surface.

• The ocean plays a large part in Earth’s environment.

• One of its largest roles is to soak up energy (heat) and distribute it more evenly throughout the Earth.

• The ocean also helps to absorb Earth’s CO2.

The ocean does an excellent job of absorbing excess heat from the atmosphere.

• The top few meters of the ocean store as much heat as Earth's entire atmosphere.

  
  

• So, as the planet warms, it's the ocean that gets most of the extra energy.

  
  

• But if the ocean gets too warm, then the plants and animals that live in it must adapt—or die.

Atoms - the basic unit of matter

- protons (positive)

- neutrons (neutral)

- electrons (negative)

2.1 The Nature of Matter

Elements

An element consists of only
one type of atom:

Examples:

C =Carbon

H = Hydrogen

Na = Sodium

6 electrons in outer shell
6 protons
6 neutrons

Compounds

- consist of two or more elements

Examples:

Water (H2O)

Table Salt (NaCl)

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Water Molecule (also a compound)

Chemical Bonds - hold
together compounds

- ionic bonds involve the
transferring of electrons

- covalent bonds involve sharing
electrons

Water Molecule

​A water molecule consists of two hydrogen atoms bonded to an oxygen atom, and its overall structure is bent.