ELEMENTS AND COMPOUNDS
• An element is a substance that cannot be broken down to other substances by
• A compound is a substance consisting of two or more elements that are
• Compounds may have entirely different properties than the elements they
are made of.
• Compounds are different than mixtures, which are made of compounds or
elements that are not chemically combined.
ESSENTIAL ELEMENTS OF LIFE
• About 25 of the 92 elements are essential to life.
• Carbon, hydrogen, oxygen, and nitrogen make up 96% of living matter.
• Most of the remaining 4% consists of calcium, phosphorus, potassium, and sulfur
• Trace elements are those required by an organism in minute quantities.
• Protons and neutrons have about the same mass.
• Protons are positively charged particles (+) that
determine the atom’s identity.
• Neutrons are particles that carry no charge and
determine the atom’s mass.
• Incredibly strong forces bind protons and neutrons
together to form the nucleus.
Chemical Elements and Compounds in Biology
There is chemistry in biology and one that goes back to the basic building blocks of the elements that are found in nature, that form what I referred to as matter (Ravagnan, Magdalena). Every other organism in nature is composed of matter. By definition matter is anything that takes up space and has mass (Chemical Compositions of Life). At the very basic level, matter is made up of elements. These are substances, which cannot be broken down to other substances, through any chemical reaction (Chemical Compositions of Life). When these elements are combined through chemical reactions, they form compounds. The two or more elements that combine to form a compound do not transfer their properties and as such, compounds in most of the cases will have different properties that those of their elements. It is important to note that chemicals are different from mixtures as the latter are not formed from chemical reactions. In an example, when sodium combines with chlorine, they form sodium chloride (Chemical Compositions of Life). The latter is a chemically formed compound between the element sodium and chlorine.
Essential Elements of Life
There are a number of ele