Origin of the Chemical Elements Flashcards
At the time of the Big Bang, what was energy converted into?
Matter and anti-matter
Was more matter or anti-matter produced during the Big Bang?
Matter
What did the matter and anti-matter do, and what did it produce?
Most anti-matter annihilated with matter to produce energy
What happened to remaining matter if it wasn’t annihilated?
It was scattered in all directions
What was the initial elemental composition of the universe?
75% hydrogen, 25% helium and very small quantities of other elements
How were protons and neutrons created?
Quarks clumped together
How were hydrogen atoms formed during the Big Bang?
Protons captured electrons
How are stars formed?
Gravity pulls hydrogen and helium together
Where were heavier elements formed after the Big Bang?
In stars
How were planets formed?
Stars burned out and exploded, expelling heavier elements such as Carbon and oxygen, that formed planets
For how long will the sun go on to produce energy?
4.5 billion years
What is nuclear fusion?
Hydrogen atoms fusing together, under intense pressure and temperatures, to form helium
What name is given to a star that is stable?
Main sequence
What is a brown dwarf?
A failed star
What two forces act on a star?
Gravity and solar radiation pressure
What is a nebulae?
A cloud of gas and dust
What is a protostar?
Formed when the gas cloud collapses under its own gravity and hydrogen undergoes fusion
What is a yellow dwarf?
A star where the solar radiation pressure acting out equals the heaving acting inwards. The stable stage of a star
Describe a black dwarf star
Very cool stage where no light is given out
Describe the blue giant stage of a star
Solar radiation pressure acting out equals the gravity acting inwards, this is the stable stage
What is a red supergiant?
Where the star runs out of hydrogen. Solar radiation pressure becomes larger than gravity and the star expands and cools
What is a supernova?
When a star runs out of fuel completely it becomes unstable, collapses and blows off its outer layer in an enormous explosion
Where do all elements with a mass greater than iron come from?
Supernovas
What is a neutron star?
The remains of a large exploding star, very dense
