Which best describes the Solar System?

The Sun and everything that orbits it

Why is a star such as the Sun stable for billions of years?

Fusion pressure balances the inward pull of gravity

A helium nucleus (2 protons and 2 neutrons)

The time for the activity to halve

So the measurement is of the source alone

Splitting a large nucleus into smaller ones

Neutrons released by fission splitting other nuclei

Joining two small nuclei to make a larger one

It produces radioactive waste that must be stored safely

14questions. Pick an answer and you'll see why right away.

What force keeps the planets in orbit around the Sun?
Which best describes the Solar System?
Why is a star such as the Sun stable for billions of years?
What is an alpha particle?
Which type of radiation is the most penetrating?
What stops beta radiation?
What is the half-life of a radioactive source?
A source has an activity of 400 Bq and a half-life of 3 hours. What is the activity after 6 hours?
Why must background radiation be subtracted when measuring a source?
What is nuclear fission?
What keeps a fission chain reaction going?
What is nuclear fusion?
Which process powers the Sun?
Which is a disadvantage of nuclear power from fission?