Basic Chemistry

What are the basic elements of all living systems?

I. Matter - Anything that has mass and takes up space

A. There are 3 basic forms of matter1) solid 2) liquid 3)gas

B. All matter is composed of elements

                                 

II. Element- a substance that cannot be broken down into simpler substancesex. oxygen, copper, nitrogen, carbon, gold

A) Each element has specific properties (traits) that are different from the other elements.

B) Elements are listed in the Periodic Table

- the periodic table organizes the elements by similar characteristics 

Periods are the horizontal rows that are numbered 1 – 7, starting from the top row. Their properties change gradually and predictably

Groups are vertical columns that contain elements with similar chemical or physical properties

- each element on the periodic table is represented by a chemical symbol. Chemical Symbols are a shorthand way of representing elements.

Examples: Symbol Name

C carbon Co cobaltN nitrogenAu gold

C) All elements are made of atoms.

III. ATOMS - the smallest particle of an element

A) Atoms have a nucleus (center)-the nucleus is made of protons and neutrons

*protons are positively charged particles

* neutrons are particles with no charge

*protons and neutrons have mass. The mass of the protons and neutrons (or the mass of the nucleus) is called the atomic mass.

*the number of protons in an atomic model is called the atomic number (SEE PERIODIC TABLE)

B) Atoms have electrons * electrons are tiny negatively charged particles that orbit (circle) the nucleus

* electrons circle the nucleus in a particular way. They travel on pathways called orbitals.

 * A compound is a substance made of different elements chemically combined

* chemical formulas represent compounds1) they show the different kinds of atoms in the compound2) they show the number of the different atom types (shown by subscript)

                                                          

Ex. NaCl2 

a) kinds: Na (sodium) Cl (chlorine)b) numbers: Na = 1, Cl = 2

B. Bonding1. Atoms combine with other atoms to form molecules and compounds.

All living things are composed of organic compounds.

Generally, organic compounds are distinguished from inorganic compounds by the presence of both carbon and hydrogen. We are referred to as carbon-based life forms, as is all life on earth. This means that carbon is a component of most of the chemical molecules that make up living organisms on this planet.