An ion is an atom with a charge which results from gaining or losing electrons

The atomic number (number of protons) DEFINES the element.

models are used in chemistry because most of the particles are too small to be seen.

Metals are malleable, sink, and conduct electricity. Non-metals are breakable, float, and do not conduct electricity.

Electrons orbit the nucleus of an atom. This area is called an electron cloud.

Electrons are leptons while protons and neutrons are hadrons.

A chemist performs two main types of tests: physical tests and chemical tests.

A hypothesis is an educated guess about the results of an experiment. In other words, to propose a model of what might happen.

From our lab, we found atoms diffuse fastest in hot water. Diffusion means to spread out or mix without being stirred.

An isotope has the same atomic number but different atomic mass.

An isotope is an element having the same number of protons, but different number of neutrons in the nucleus. A great example is Carbon.

The atomic mass is the average mass of an atom.

The atomic number represents the number of protons found in the nucleus of a articular type of atom.

A periodic table is an arrangement of elements according to their atomic number.

An element is a group of the same type of atoms.

Protons have a positive charge. Electrons have a negative charge. Neutrons have a neutral charge.

An atoms is made up of protons, neutrons and electrons. Protons and neutrons are found in the nucleus.

Air is comprised of two major parts of atoms: nitrogen and oxygen.

A molecule is formed when atoms join together. An example is water- 2 atoms of hydrogen joined to 1 atom of oxygen.

A scanning-tunneling microscope is a special type of microscope allowing you to see atoms.

A theory is something scientists believe will happen.

Democritus said everything was made from particles called atoms. All things could be broken down into smaller pieces until you reached atoms.

Cells are the building blocks of all life and they are made up of atoms.

Everything in the universe is made of atoms. They are the basic building blocks of all matter.

A chemist is a person who studies chemistry.

Chemicals are all around you. All things seen and unseen are made if chemicals.

Chemistry is the science that studies chemicals.