Names
Understanding Water by Comparison to Methane
Hydrogen atoms have a single electron
orbit (called orbital), and a single electron.
orbit (called orbital), and a single electron.
Atoms are unstable unless they have two electrons in each orbital. To get a second electron in
an orbital, an atom can “share” electrons with another atom. Sharing electrons forms a
chemical bond (a “covalent” bond).
an orbital, an atom can “share” electrons with another atom. Sharing electrons forms a
chemical bond (a “covalent” bond).
Because carbon atoms have one electron in each
orbital, they can (and must) form 4 bonds.
orbital, they can (and must) form 4 bonds.
Carbon
atom
atom
Oxygen
atom
atom
Draw the molecules that would be produced if carbon and oxygen formed bonds with
hydrogen, to make methane (CH4) and water (H2O).
hydrogen, to make methane (CH4) and water (H2O).
The atomic nucleus contains protons, and is positively charged (+). Draw + symbols on the
atomic nuclei in your drawings.
atomic nuclei in your drawings.
Electrons are negatively charged (-). Draw - symbols near the electrons in your drawings.
1. How is methane (CH4) different from water (H2O)?
2. How do the electrons influence this difference?
3. Predict which of these molecules will be “polar” and which will be “non-polar”
(“polar” means that the molecules, overall, have a + end, or pole, and a - end, or pole).
4. How does this affect the ways these molecules will interact with other molecules? On a
new piece of paper, draw a group of water molecules and some methane molecules, showing
their interactions.
new piece of paper, draw a group of water molecules and some methane molecules, showing
their interactions.
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