Building a Water Molecule

In the picture

1. 1Oxygen atom — the large red sphere at the centre of the model.
2. 2Hydrogen atom — the smaller white sphere on the left.
3. 3Chemical bond — the short grey rod joining that white sphere to the red one.
4. 4Liquid water in the beaker — billions of these three-atom units together.

Examples

• The water you drink from a glass is made of these H₂O molecules.
• Steam from a boiling kettle is the same molecules, moving fast and spread far apart.

Quiz: Building a Water Molecule (Age 13)

1. 1

   Water is written as H₂O. What does that formula tell you about one water molecule?

   • It has two hydrogen atoms joined to one oxygen atom
   • It has two oxygen atoms joined to one hydrogen atom
   • It has just two atoms in total, one hydrogen and one oxygen
2. 2

   How are the three atoms in a water molecule arranged?

   • They lie in a straight line, with the oxygen atom in the middle
   • They form a closed ring, with every atom bonded to both of the others
   • The two hydrogen atoms join the oxygen atom at an angle, so the molecule is bent
3. 3

   What is a beaker of liquid water actually made of?

   • One single enormous water molecule that fills the whole beaker
   • Billions of separate water molecules, each made of three atoms
   • Loose hydrogen and oxygen atoms that are not joined to one another

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.