Where Does Chemistry Come From Flashcards
After one second of the Big Bang, what happens?
The forces explode which leads to expansion and temperature decrease.
What are the four main forces?
- Gravity.
- Electromagnetism.
- Strong nuclear force.
- Weak nuclear force.
After the Big Bang, why is there less kinetic energy?
Because there is a decrease in temperature.
After the Big Bang, what occurs after kinetic energy has decreased?
A proton and an electron can join each other together.
What is the first element to ever be created?
Hydrogen.
Hydrogen is the most abundant chemical element in the Universe. By what percentage is normal matter composed of Hydrogen?
75%
Hydrogen is the most abundant chemical element in the Universe. What percentage of atoms are Hydrogen?
90%
Helium is formed from four Hydrogen’s. Is this an exothermic or endothermic reaction?
Exothermic.
What happens to the energy produced from the formation of Helium?
The energy leads to an increase in temperature that fuels further reactions.
What type of force is critical to overcome the electrostatic repulsion between protons?
Strong nuclear force.
What is the second element to form?
Helium.
Who proposed a mechanism for the synthesis of heavier atoms?
Sir Fred Hoyle.
What three elements where thought to be made in stars by fusion of He atoms?
Carbon, Nitrogen and Oxygen.
What three elements were the reaction intermediates for making heavier atoms?
Carbon, Nitrogen and Oxygen.
Within a star, where is pressure and temperature the highest and why?
It is highest at the core because it is the most dense.
Where in a star are atoms produced?
In the core.
As heavier atoms are made, what increases within the star?
The density of the core.
What happens to temperature and pressure as heavier atoms are made?
They both increase.
What element causes the stars core to collapse?
Iron.
Once Iron synthesis has been achieved, what type of explosion occurs?
A supernova explosion.
What occurs as a consequence of a supernova explosion?
An extreme amount of energy is released and this initiates the synthesis of all the other chemical elements heavier than Iron.
State the five stages of life and death of a star.
- Matter particles left over from the big bang are brought together by gravity.
- The large clouds collapse in on themselves until at 10 million degrees.
- The Hydrogen fuses to make a star.
- When Hydrogen runs out, the other elements are fused at increasingly higher temperatures until Iron is reached.
- When Iron is reached, a supernova explosion occurs.
Why is the Universe close to thermal death?
The Universe has cooled down to -222°C and so has lost most of its kinetic and thermal energy.
