5.1 What are atoms, elements and compounds?

Front

What is the Greek word from which 'atom' is derived, and what does it mean?

Back

atomos, meaning 'indivisible' or 'uncuttable'

Front

What percentage of all the atoms in the universe come from the two lightest elements?

Back

More than 98%

Front

What happens at the end of a large star's lifecycle that contributes to the creation of heavier elements?

Back

It undergoes a massive explosion called a supernova.

Front

What discovery allowed scientists to view images of different atoms that had previously been unseen?

Back

The development of the scanning tunnelling microscope

Front

What would happen if you cut an atom of silver in half?

Back

You would no longer be in possession of the element silver

Front

What are elements considered to be?

Back

Pure substances.

Front

What is the name of the microscope that allowed scientists to view the first image of an atom?

Back

Scanning tunnelling microscope.

Front

Which of the following is true about compounds?

• They are made of one element combined in a fixed ratio by weight.
• They have the same properties as the elements they are made of.
• They are formed when two or more elements combine with one another by chemically bonding.
• They are always in the gaseous state.

Back

They are formed when two or more elements combine with one another by chemically bonding.

Front

What is the origin of the symbol 'W' for the element tungsten?

Back

It comes from its Latin name 'wolfram'.

Front

Why do some symbols for chemical elements in the periodic table not match their English name?

Back

Because they are taken from the elements' Latin or Germanic names.