2. Introduction to The Sun Our sun is a star located at the center of our Solar System. It is a huge, spinning ball of hot gas and nuclear reactions that light up the Earth and provides us with heat. The Greeks called the Sun "Helios"; the Romans called it "Sol."Solar System

3. COMPOSITION OF THE SUN The Sun is made up of gases. It is composed of about 75% hydrogen and 25% helium. About 0.1% is metals ). The Sun formed 4.5 billion years ago

4. THE TEMPERATURE OF THE SUN The Sun's core can reach 10 to 22.5 million degrees Fahrenheit. The surface temperature is approximately 9,900°F. The outer atmosphere of the Sun gets extremely hot again, up to 1.5 to 2 million degrees. The temperature of the Sun is determined by measuring how much energy (both heat and light) it emits.

6. The Sun’s ENERGY PRODUCTION At the Sun's core the changing hydrogen into helium produces large amounts of energy. This is called nuclear fusion.hydrogenhelium nuclear fusion Nuclear fusion releases an enormous amount of this heat and light energy into the Solar System (including Earth).

7. AGE OF THE SUN The Sun formed 4.5 billion years ago, as the solar system coalesced from a cloud of gas and dust.

8. 1. Is the Sun a star, a planet, or a nebula?_______________________ 2. Is the Sun solid, liquid, or gaseous ?_______________________ 3. What did the Greeks call the Sun?________________________ 4. Where is the Sun hottest?_______________________ 5. Where is the Sun coolest?_______________________ 6. What element is there the most of on the Sun?_______________________ 8. What is the name for what happens when the Sun changes hydrogen atoms into helium atoms? _______________________ 9. How old is the Sun? ______________________