The formation of elements

fusion in stars

• most of their lives, stars fuse elemental hydrogen into helium in cores

• two atoms of the hydrogen are combined in a series of steps to create helium-4

• theses reactions account for 85% of the suns energy

equation for nuclear fusion

What does a star emit due to nuclear reactions?

All wavelengths of the electromagnetic spectrum and energised particles (including protons and neutrinos)

What is solar wind?

A stream of energised particles (mainly protons and neutrinos) released from a star

How does energy from the Sun affect Earth?

It warms the planet, drives weather, and provides energy for life

How is Earth protected from harmful radiation and solar wind?

The atmosphere absorbs most harmful radiation, and the magnetic field deflects charged particles from the solar wind

What happens when a star’s core runs out of hydrogen?

• the star begins to die die out

• the dying star expands into a red giant

• this now begins to manufacture carbon atoms by fusing helium atoms

How do more massive stars fuse elements?

• they begin a further series of nuclear burning or reaction stages

• the elements formed in these stages rane from oxygen to oxygen through to iron

How do elements form during a supernova?

• the star releases very large amounts of energy as well as neutrons which allows elements heavier than iron such as uranium and gold to be produced

• in the supernova explosion all of these elements are expelled out into space

How do 3 helium fuse to give a carbon?

How does carbon and helium fuse to give oxygen?

How does oxygen and helium fuse to give a neon atom?

How do neon and helium fuse to give magnesium?

How many known elements occur naturally?

90/116

What happens when fast neutrons collide with uranium-238 (U-238) in a reactor?

A new element, plutonium, is formed

Where does the production of plutonium from U-238 occur?

In nuclear reactors (nuclear power plants)

How do particle accelerators create new elements?

By smashing atoms together at high speeds

Give an example of an element made using a particle accelerator

Seaborgium (element 106), made by bombarding curium with neon

Where were most elements in the universe originally formed?

In the cores of stars that are now long dead