Atoms and Periodic table

Atoms are the smallest particle of an element. Each element is made of only one kind of atom. For example, gold is only made of gold atoms and neon is only made of neon atoms. The overall shape of all atoms is spherical (like a basketball), but they vary in size.

Atoms are made of three different kinds of sub-atomic particles: protons,neutrons, and electrons.

Protons have a positive (+) charge, and each has a mass of one “atomic mass unit” (amu).

Neutrons have no charge (sometimes stated as a neutral or zero (Ø) charge), and each also has a mass of 1 amu

Electrons have a negative (-) charge, and a very tiny mass of 0.005 amu. The mass of electrons are so small that they are usually ignored when adding up the mass of the entire atom to state the atom’s atomic mass.

Have a periodic table

Identify the element that is being asked for

look for atomic number, atomic number should be on top of atomic symbol and that will provide the # of protons and # of electrons

Look for atomic mass, that should be under atomic symbol, this will provide the # of protons & neutrons since they make up most of the mass of the atom

To find number of neutrons, subtract the atomic number from the atomic mass and that will provide number of neutrons

An element is a substance that cannot be separated into simpler substances byphysical or chemical means. An element is already in its simplest form.

The Periodic Table of Elements is a list of all the elements that have been discovered and named, with each element listed in its own element square.

The horizontal (left-to-right) rows of the periodic table are called periods. There are seven periods in the periodic table.  

Within each period, all elements have the same number of occupied Bohr Modelelectron “shells” (electron energy levels or orbitals).

The vertical (up-and-down) columns indicate the 18 different groups or chemical families of the periodic table, usually numbered 1 through 18, from left to right. The elements within each group have the same general chemical properties and the same number of valence electrons in the Bohr Model outer electron “shell.”