Where Elements Come From Flashcards
What are the primary elements that compose Earth and terrestrial planets?
Earth and terrestrial planets are primarily composed of iron (Fe), magnesium (Mg), silicon (Si), and oxygen (O).
What elements dominate the composition of stars?
Stars are mostly made of hydrogen and helium.
Why are hydrogen and helium dominant in the universe?
Hydrogen and helium were the significant elements formed after the Big Bang, accounting for most of the universe’s matter.
What are the prerequisites for habitability on a planet?
Habitable planets need solid or liquid surfaces and an abundance of carbon (C).
How does star formation begin?
Stars form from the gravitational collapse of gas clouds.
How do we determine the sun’s chemical composition?
By observing spectral lines in the sun’s spectrum, which indicate element absorption and abundance in the sun’s atmosphere.
What is the relative abundance of elements in the sun?
Hydrogen and helium dominate, followed by a decline in abundance with increasing element number, with iron being unusually high and lithium, beryllium, and boron significantly lower.
How did galaxies form according to the Big Bang theory?
Hydrogen and helium clouds merged into megaclouds, forming galaxies, which comprised billions of stars formed from smaller subclouds.
Where are elements heavier than helium primarily produced?
Elements heavier than helium are primarily produced inside stars over billions of years.
What forces hold the atomic nucleus together?
The strong force holds protons together in the nucleus, and neutrons stabilize the nucleus by separating protons.
What is the band of stability?
The band of stability is a chart of nuclides where stable nuclei form a band, with radioactive nuclei decaying into stable configurations.
What occurred during the neutron-proton transformation after the Big Bang?
Neutrons decayed into protons plus electrons every 10.2 minutes, and stable neutrons collided with protons to form deuterium and helium isotopes.
Why are there few elements heavier than helium produced immediately after the Big Bang?
There are no stable nuclei of mass 5 or mass 8, making reactions to produce heavier elements rare.
How do stars generate energy?
Stars generate energy through nuclear fusion, where atomic nuclei collide at high velocities, overcoming electrostatic repulsion and fusing together, releasing energy.
What happens to small stars like our sun as they age?
Small stars sustain hydrogen burning for billions of years before becoming red giants and undergoing helium fusion to form carbon.
