Earth and Beyond (Assignment 6) Flashcards
What is a NEBULA?
Cloud of dust and gas
…..beginning stage of a star***
Explain what the ‘Great nebula of Orion’ is
** 20 light years across
** contains enough material to move several
hundred stars like our sun
The sun is the Earth’s nearest star. Mention a few things about the birth of the Sun
= it takes 4 million years to form
= gravity pulled gas & dust into matter
= in the centre it grew bigger
= smaller matter formed planets and moons
= the centre become hotter and formed the sun
NB = Why does a star become hotter when it is
forming?
- The force of gravity compacts the matter in the
nebula - Pressure on the particles causes them to heat up
What is the difference between :
nuclear reaction & nuclear fusion reaction?
Nuclear reaction (ATOMIC BOMB):
Nuclei of atoms interacts with others (SAME) by
combining OR
splitting
Nuclear fusion:
Joining of DIFFERENT nuclei of atoms to form larger nuclei of NEW elements (eg: hydrogen nuclei fuse to form HELIUM)
Explain an OLD STAR
Red
Cooler than a new star
3000 degrees Celsius
Explain a NEW STAR
Blue white
Very hot
15 000 degrees Celsius
What is the lifespan of a star, like the Sun?
9 billion years
How long ago was the Sun formed?
4500 million years
What will be happening on the Sun for the next few thousand million years?
- BIGGER
- turn RED
What colour are the YOUNGEST and HOTTEST stars?
Blue white
What colour are the OLDEST and COOLEST stars?
Red
Explain what happens when a star DIES
- Gravity stops pulling matter to the centre of the
star - Nuclear reactions SLOW down
- Star turns red
- Now called a RED GIANT
What is a STAR called that has DIED?
Red giant
What is a ‘white dwarf’?
Final stage in the life of a star.
