Atoms and molecules
Answers are for parents and teachers.
1
How many atoms are in two water molecules and one CO₂ molecule in total?
9
2
Why does sugar stay sweet even when ground?
Because ground sugar still consists of unchanged sugar molecules; sweetness is a property of the molecule.
3
An oil drop has volume 0.004 mm³ and the spot has area 20 000 mm². What is the layer thickness (in mm)?
0.0000002 mm
4
Write the difference between an atom and a molecule in 2 sentences.
A molecule is the smallest particle that keeps a substance’s properties; it consists of one or more atoms. An atom is made of a nucleus and electrons.
5
What did Beruni and Ibn Sina say about the division of the atom? Write 2–3 sentences.
Beruni asked about it, saying division can be neither impossible nor endless; Ibn Sina said division has a limit.