Year 10 Science · Unit 2 · Lesson 22

The Big Bang and Formation of the Elements

Foundation Worksheet

Name

Date

Class

Learning Goals

Recall which elements formed in the Big Bang and which formed later in stars.
Sort elements and processes into where they were made in the Universe.
Describe the main evidence that supports the Big Bang model.

Warm Up

Fill the gap

Choose the correct word from the word bank to complete each sentence. Two words will NOT be used.

hydrogen helium iron fusion supernova cooling microwave gravity oxygen uranium

The Big Bang happened about 13.8 billion years ago in a hot, dense state that has been expanding and ever since. In the first few minutes the lightest element, , formed first, followed by and a trace of lithium. Heavier elements were not made in the Big Bang. Inside stars, nuclear joins light nuclei together and releases energy. Fusion in stars builds elements up to , the most stable nucleus, but no further. Elements heavier than that form in a explosion. One key piece of evidence for the Big Bang is the cosmic background radiation that fills all of space.

Your Turn

Sort it!

Write each element or process from the pool into the correct box. Each one belongs to exactly one place.

Hydrogen Helium Lithium (trace) Carbon Oxygen Iron Gold Uranium First few minutes of the Universe Hydrogen fusing to helium Neutron-star mergers Star runs low on hydrogen

Made in the Big Bang

Made by fusion inside stars (up to iron)

Made in supernovae (heavier than iron)

Show What You Know

1. Which two elements made up almost all of the early Universe, and roughly what percentage was each (by mass)?

Recall 2 marks

2. Why is iron, ⁵⁶₂₆Fe, the heaviest element that ordinary fusion in a star can make?

Recall 2 marks

Wrap Up

In one sentence, explain what people mean when they say "you are made of stardust".