If the sun is a burning ball of gas … just what

gas is it burning?

Warmup Question:

The SunComponents &

Nuclear Fusion

The Sun’s Composition

• The sun is a massive, luminous ball of burning gas.– Remember – burning does not destroy matter, it

releases energy and changes the matter it into something else: wood ashes, dough cookies

• Gasses found in the Sun:– Hydrogen 75%– Helium 24%– Oxygen <1%– 64 more elements make up the rest

Our book lists Hydrogen at 75% - most other sources are closer to 71%.

The Periodic Table

Nuclear Fusion• “Normal” Hydrogen

atom (75% of the sun)• One PROTON• One ELECTRON• Inside the Sun – the

intense heat strips the atom of its electron.

• This is now a 1H Hydrogen Nucleus

P

e

Nuclear Fusion – Part 1

P

PNp

One proton loses its charge and becomes a neutron.

This is now 2H Hydrogen.

A positron is formed & released.

Two 1H Protons collide!

nA neutrino is

formed & released.

Energy Released!!

Nuclear Fusion – Part 2

This forms 3He HELIUM – a NEW element is formed! Helium is 24% of the sun.

Hydrogen 2H colides with another loose Proton.

N

P

P

Energy Released!!

Nuclear Fusion – Part 3

Two Protons are knocked loose.

This forms 4He HELIUM.

Helium 3He collides with another Helium 3He

N

P

P

N

P

P

Energy Released!!

Those loose Protons are now a 1H Hydrogen Nucleus – they are recycled back into the Hydrogen pool to be turned into Helium again.

Review

• Gasses found in the Sun:– Hydrogen 75%– Helium 24%– Oxygen <1%– 64 more elements make up the rest

Scientists estimate the age of a sun by how much hydrogen it has left.

Nuclear Fusion

• (6) Hydrogen (1) Helium + (2) Hydrogen(plus a few positrons and neutrinos released)

• Produces most of the sun’s energy• Energy released causes the sun to shine and

gives off high temperatures• Elements other than hydrogen can fuse• In stars that are hotter than the sun, energy

is produced fusing carbon, nitrogen, and oxygen.

Einstein

• 1905 proposed that a small amount of matter can yield a large amount of energy.

• Nuclear fusion was unknown.• The nucleus of an atom was

unknown.• And yet his theory explained

how the sun can give off so much energy without burning out too soon.

Einstein & E=mc2

• E = energy

• m = mass

• c = speed of light

• Einstein’s equation can be used to calculate the amount of energy produced from a given amount of matter.

• The sun turns more than 600 million tons of hydrogen into helium every second.

So – do you know now?

If the sun is a burning ball of gas … just what

gas is it burning?

Warmup Question: