Helping those who are in need of help with various Chemistry related topics...
Chemistry is the study of matter and its composition. Chemistry is also the study of what happens when matter interacts with other matter. Matter is anything that has mass and volume -- meaning it is either a solid, liquid, or gas. Characteristics that help you describe and identify matter are called "properties". An example of properties include physical state, color, odor, texture, boiling temperature, density, and combustibility. A physical property is a property that you can observe without changing one kind of matter into something new, while a chemical property is a property that you can observe when one kind of matter is converted into a different kind of matter.
Element -> a pure substance that cannot be separated chemically into any simpler substances.
Compound -> a pure substance that results when two or more elements combine chemically to form a different substance.
Atom -> the smallest particle of an element that still retains the identity of the element.
Protons & Neutrons -> clustered together to form the central core, or nucleus, of an atom. Protons have a positive charge, while neutrons do not carry a charge (they are said to be neutral).
Electrons -> the fast moving particles that occupy the space that surrounds the nucleus of an atom. Electrons are negatively charged.
Atomic Mass Unit -> used to compare the mass of subatomic particles.
Mass Number -> the total number of protons and neutrons in the nucleus of one of its atoms.
Atomic Symbol -> each element has a different atomic symbol, all Chemists around the world use the same atomic symbols.