EL 1 Where do chemical elements come from

What is the Big Bang theory?

It is the theory that the universe began from a single point and exploded

What are the main elements formed after the Big Bang?

Hydrogen and helium were the main elements formed in the early universe.

What is nuclear fusion?

A process where lighter nuclei like hydrogen fuse to form heavier nuclei such as helium releasing energy.

What happens in a supernova?

A massive star explodes

What are the stages of a lightweight star like the Sun?

The Sun will expand into a red giant then become a white dwarf after burning all its hydrogen.

What is a white dwarf?

A small dense remnant of a star that has shed its outer layers after expanding into a red giant.

What is the life cycle of a heavyweight star?

A heavyweight star forms heavy elements through fusion ends in a supernova and disperses elements into space.

What happens when a star turns into a supernova? The core collapses heavy elements are formed and the outer layers explode into space.

What are isotopes?

Atoms of the same element with different numbers of neutrons and different mass numbers.

What is relative atomic mass?

It is the weighted average mass of an element's isotopes

What is mass spectrometry?

A technique used to measure the relative abundances of isotopes and determine the relative atomic mass of an element.

How is relative atomic mass calculated using mass spectrometry?

The relative atomic mass is the average mass of an element's isotopes taking their relative abundances into account.

What is a proton's charge?

A proton has a charge of +1.

Where is the neutron located in an atom?

Neutrons are located in the nucleus of an atom.

What is the charge of an electron?

An electron has a charge of -1.

What particles make up the nucleus of an atom?

Protons and neutrons make up the nucleus of an atom.

What is the atomic number of an element?

It is the number of protons in the nucleus of an atom and determines the element's identity.

What is the mass number of an atom?

The mass number is the total number of protons and neutrons in the nucleus.

What happens when iron nuclei fuse together in a star?

Iron nuclei absorb energy and fusion stops releasing energy leading to a star's collapse.

What happens to a star when it has consumed all its hydrogen?

It expands into a red giant

What is a red giant?

A star in its late stage of evolution that expands after depleting its hydrogen fuel eventually shedding its outer layers.

What are the conditions needed for nuclear fusion in stars?

High temperature and pressure are required to overcome the repulsion of positively charged nuclei.

How do elements like carbon nitrogen and oxygen form in stars?

They are produced through nuclear fusion in the cores of stars especially in heavier stars.

What role do electrons play in chemical reactions?

Electrons in the outermost shells of atoms interact to form chemical bonds and reactions.

What was the initial state of the universe according to the Big Bang theory?

All matter and energy were contained in a single point before the explosion.

How long after the Big Bang did the first atoms form?

Atoms began forming about 10 000 years after the Big Bang.

What are protons and neutrons made of?

They are made of quarks which are held together by the strong force.

What is a star’s energy source?

Stars get energy from nuclear fusion reactions occurring in their cores.

What happens when stars with heavy elements explode in a supernova?

They scatter heavy elements like iron gold and uranium into space enriching the interstellar medium.

How does mass spectrometry help determine isotopic abundance?

It separates ions by mass and measures the relative abundance of isotopes to calculate the relative atomic mass.

How do scientists know about the structure of the atom?

Through experimental evidence and the development of scientific models over time.

How do nuclear fusion reactions produce energy in stars?

Fusion reactions release energy when lighter nuclei combine to form heavier nuclei such as hydrogen into helium.

What was the model of the atom proposed by Rutherford?

The Rutherford model proposed that atoms have a small dense nucleus surrounded by orbiting electrons.

What is a model in science?

A model is a simplified representation that helps explain and predict phenomena but it is not necessarily the absolute truth.

What is the relationship between mass number and atomic number?

Mass number = Atomic number (protons) + number of neutrons.