Energy from the Sun •The Sun’s energy gives us heat through conduction, convection, radiation

•The Sun’s energy also gives us light through electromagnetic radiation

How hot is the Sun?

• The Sun’s core is 15 million °C (27 million degrees ° F )

How does the sun produce energy?

•The sun is made entirely of gas

•The Sun produces energy through a process called nuclear fusion - in this process, hydrogen atoms are fused together to make helium atoms

Nuclear Fusion

•Nuclear fusion is the combination of two lighter atoms into a larger one.

Hydrogen Atom (1 proton)

Hydrogen Atom (1 proton)

Helium Atom (2 protons)

H+ + H+ = He++ + Energy

Nuclear Fission •Nuclear fission is the division of one atom into 2 atoms. This releases a very large amount of energy -> FISSION IS DIVISIO

•Example: 1 atom of a Uranium isotope will split into Krypton and Barium atoms

1 atom

2 atoms

U= Kr + Ba + Energy

Nuclear Fission vs Fusion

Heat •Thermal energy is created by the movement of atoms or molecules

•What is heat? Heat is the result of thermal energy being transferred between atoms or molecules

•Where does heat come from? Heat is generated because of differences in the energy of atoms or molecules

•The faster these particles move, the more heat is generated

Heat=Energy Transfer •Heat is created when energy is transferred. •There are 3 methods of energy transfer: 1.Conduction- energy is transferred when molecules from one object collide with molecules of another object

2.Convection- energy is transferred by circulation with in fluids and air

3.Radiation- energy is transferred by waves of electromagnetic energy

•Unlike conduction, waves of radiation can travel

through space •Heat travels from high energy to low energy

•All objects, regardless of temperature, emit radiant energy

•If an object is hot, it will emit more total energy than a colder object

•Hotter objects produce short wavelengths

•Colder objects produce long wavelengths

Radiant Energy= Radiation

Temperature

•Temperature is a measurement of energy

Light from the Sun •Light from the sun travels in waves of radiation.

•We call these radiation waves Electromagnetic Waves

Waves of Radiation •Electromagnetic radiation includes 6 major Electromagnetic Waves

1. Gamma Rays

2. X-Rays

3. Ultraviolet Rays

4. Visible light

5. Infrared Rays

6. Radio Waves

Electromagnetic Spectrum •The waves are arranged according to the length of their wave and frequency

1. Gamma Rays

2. X-Rays

3. Ultraviolet Rays

4. Visible light

5. Infrared Rays

6. Radio Waves

What happens after radiation is emitted from an object?

•An object will:

1. Absorb radiation

2. Transmit radiation

3. Scatter radiation

4. Reflect radiation

If an object is good at absorbing radiation, it is also good at emitting radiation

Earth’s Atmosphere

• Size= Earth’s atmosphere begins on Earth’s surface and extends about 600 miles upward. •Composition=Our atmosphere is made of a mixture of gassy elements, water vapor, and tiny solid particles

•Most of the gases exist between 0-3.5 miles of Earth’s surface

• Layers= The atmosphere is made up of 4 major layers and each layer is divided by temperature.

Composition- original gases

• The most abundant gas in the atmosphere is Nitrogen at 78% •Oxygen makes up 21% of our atmosphere •Carbon Dioxide, Argon, and other gases exist in small amounts •The amount of gases decrease and the atmosphere thins as you travel away from the surface

Composition

•Around 4 billion years ago, Earth had no atmosphere.

•Our surface was covered with volcanoes that released gases during eruptions

Composition- Oxygen

•Oxygen is new in our atmosphere!

•Oxygen in our atmosphere is the result of plants and algae making food by photosynthesis

•Plants combine carbon dioxide (CO2) and radiation from the Sun to make their food.

•During the photosynthesis (food making process), oxygen is released.

Layers- Height •Our atmosphere has 4 major layers and 1 minor layer

1. Troposphere- 0-6 miles

2. Stratosphere-6-30 miles a) Ozone Layer

3. Mesosphere – 30-50 miles

4. Thermosphere- 50+ miles

Layers- Temperature •Each layers is divided vertically by temperature

1.Troposphere- temp with height

2.Stratosphere-temp with height

3.Mesosphere – temp with height

4.Thermosphere- temp with height

Layers- Ozone Layer •Within the stratosphere is the ozone layer.

•This is a group of ozone gas molecules (O3) that absorb harmful UV (ultraviolet) radiation waves from the sun.

•If ozone did not absorb and filter UV radiation, many living organisms could not survive on Earth