a ball of very hot gas and plasma that emits radiation and is powered by nuclear fusion in its core

the process of merging small nuclei into larger nuclei with the release of energy

a region of space containing traces of gas (mostly hydrogen) and dust

a dense, hot, ball of gas formed by a collapsed nebula

the stable period of a star when it is fusing hydrogen in its core

Birth of a star

Physics

The solar system

Orbital motion of artificial satellites: relationship between radius and speed

Stellar evolution

Observing the universe

The changing universe

In the Solar system and beyond unit, pupils learnt about the scale and content of the Solar system and the universe, and about gravitational force and the motions that cause days and seasons on the Earth.

This unit covers the solar system's features, including planets, moons, and satellites. It explains gravity's effect on orbits, the sun's formation from dust and gas, and fusion equilibrium. It also explores red-shift, evidence of an expanding universe, and the link to the Big Bang model.

Gravity in space

How does the size of the Sun compare to the size of other stars?

The Sun is one of about 300 billion stars in the {{}} galaxy.

What sort of reaction inside the core of a star causes it to become very, very hot?

A huge spinning ball of very hot, dense gas that forms from a collapsing nebula is called a {{}}.

A nebula is disturbed and starts to collapse.

Gravitational forces accelerate particles of gas and dust towards each other.

The particles move faster as they come together and the nebula heats up.

A hot dense spinning ball of dust and gas forms, which is called a protostar.

If nuclear fusion begins in the core, it becomes a star.

Put each stage in the early life of a star in the correct order, starting with the first.

The Sun is a huge ball of gas and the gas is burning.

Nuclear reactions in the Sun make it hot and bright.

Which of these statements about the Sun are correct?

all stars have points and are ‘star-shaped’

some stars are spherical, and some are ‘pointy’ and ‘star-shaped’

stars have a range of different shapes, including spherical and ‘star-shaped’

What would the Sun look like if it were two times further away?

Why do stars appear to move across the night sky, with their movement repeated once each day?

all of the stars are on the far side of Earth, away from the Sun

light from the Sun makes the whole sky brighter than individual stars

a large spherical object that orbits a star

a very hot ball of gas and plasma that emits light radiation

a group of billions of stars clustered together in space

Match each object in space to the correct description.

Exit Quiz

How does the size of the Sun compare to the size of other stars?