CRCT QUESTIONWhat kind of weather is associated when a cold front approaches an area?

A. sunny skiesB. drizzly rainC. thunderstorms, heavy rain,

or snowD.hot, muggy weather

AGREE OR DISAGREE 1. The universe is about 13.7 million years

old2. The milky way is a spiral galaxy3. Stars are classified according to age,

picture, temperature 4. Blue-white stars are the hottest 5. Astronomers believe that the universe is

expanding 6. We use radiation as evidence that the

galaxies are moving apart 7. Salinity of the ocean is approximately 35%

Are stars still present in the sky during the day time?

Yes, we just can’t see them because their dim light is

overwhelmed by the brightness of the sun during the day.

GALAXIES ARE BASED ON THEIR:

Size

Shape

Brightne

ss

Densit

y

11%6%6%

78%1. Size2. Shape3. Brightness4. Density

What is it most based on?

Life Cycle Of

Stars Video

viI. How a star is born?

A. NEBULAS

As the particles pull closer together the temperature increases.

At 10,000,000o C fusion takes place and energy radiates outward through the condensing ball of gas.

Another view of Orion

B. HYDROGEN FUSION: ENERGY OF THE STARS

Stars have large amounts of hydrogen gas.

4 hydrogen atoms fuse forming 1 atom of helium

The mass of 4 hydrogen atoms is greater than the mass of 1 helium atom; the excess mass is converted to a tremendous amount of energy.

THIS HYDROGEN HELIUM FUSION CAN POWER A STAR FOR BILLIONS OF YEARS

C. RED GIANT Fusion uses up a star’s hydrogen supply

rapidly casing the core to heat up and the outer temperature to fall. (Life cycle of the star)

Star expands and becomes a red giant

Red Giant

D. STELLAR EVOLUTION

Core continues to heat and star expands to a super giant.

As the core uses up its helium supply, the outer layers escape into space and the remaining core is white hot and called a white dwarf.

White dwarfs

E. STELLAR EVOLUTION When no more material is left in the core it

explodes into a supernova. Smaller stars become neutron stars and most

massive will collapse into a black hole.

Neutron Star

BLACK HOLES-NOTHING CAN ESCAPE, EVEN LIGHT!