1. Basic Chemistry Concepts
• Ions
– When there is an imbalance in the number of
protons and electrons of an atom, the resulting
atom or molecule is called an ion. Ions are
commonly formed, for example, when a
compound dissolves in water.
– A cation is a positively charged ion (missing
electrons) and an anion is a negatively charged
ion (has surplus electrons).
– If no number is given and there is just a + or -
then there is an imbalance of only one (1)
electron.
• CaCo3→Ca2+ + CO3
2- Where: CaCo3 = Calcium
Carbonate
• Ca2+ = Calcium (cation), CO3
2- = Carbonate
(anion)
2. Basic Chemistry Concepts
• Chemical reactions
– Chemical reactions occur when atoms are rearranged
to form new molecules or compounds. For example,
carbon dioxide and water can combine to form a
sugar (as in photosynthesis).
• 6CO2 + 6H2O + energy → C6H12O6+ 6O2
• (Note that since energy is required to make the reaction
happen, this energy is released when the sugars are
broken down. this energy-releasing equation is called
respiration and is what happens in our bodies—and in
some form in all organisms—all the time.)
– Redox reactions are paired oxidation and reduction
reactions that are very common and important in
nature. oxidation occurs when an element or molecule
loses an electron, and reduction occurs when another
element or molecule gains the electron. the electron
donor is said to be oxidized and the electron acceptor
is reduced.
3. Basic Chemistry Concepts
• Adsorption vs. absorption
– Adsorption means to be held onto the outside
of something. In soils this refers to how ions are
held to the outer surfaces of mineral and
organic particles.
– Absorption means to be taken up into
something, such as water being taken up by a
sponge or nutrients being taken into plant roots
• Organic vs. inorganic
– In chemistry, organic refers to many kinds of
compounds containing carbon, which may be
natural or synthetic (human-made).
• Many of the synthetic pesticides used are “organic”
by this definition.
– Inorganic refers to compounds not classified as
organic
