Atoms, Elements, and Molecules…..Oh My!

Matter Anything that has mass and takes up space – Mass: How much matter is in an object – Volume:How much space an object takes up

Atoms Smallest basic unit of matter Basic building blocks of matter 1 tsp of H 2 0 contains approximately 500,000,000,000,000,000,000,000 atoms

Parts of an Atom Nucleus—the center of the atom, composed of protons and neutrons Protons—located inside the nucleus and have a POSITIVE charge Neutrons—located inside the nucleus and have NO charge Electrons—located outside the nucleus and have a NEGATIVE charge

ParticleElectrical Charge SymbolAtomic Mass Unit (AMU) Location in Atom Proton1 amu n/a1 amunucleus negative0 Check what you know … *Draw the table *Fill in the empty boxes

Elements Characteristics are determined by the structure of its atoms Each element is made up of atoms that differ from every other element

Element Features 1. Atomic number—describes the number of protons in the nucleus of an atom – No two elements have the same atomic number – Atomic number also equals the number of electrons in an atom 2. Atomic Mass—is equal to the number of protons plus the number of neutrons in the atom’s nucleus 3. Chemical Symbol—is a code composed of one or two letters that represents an element – Each element has its own chemical symbol – Example: C= carbon, Fe = iron

2 Rules 1. Protons + Neutrons = the atomic mass P + N = AM 2. Protons, Electrons, and the Atomic Number are always the same number If you know one of the numbers, you know all 3

ElementSymbolProtonsNeutronsElectronsAtomic Mass Carbon66 Oxygen816 amu Sodium1122 amu Potassium1920 Iron2656 amu Check what you know… *Draw the table * Fill in the empty spaces

Molecules Two or more atoms bonded or combined together Can be made up of atoms that are different or atoms that are alike – Example: water is a combination of different atoms—2 hydrogen atoms and 1 oxygen atom written (H 2 O) – Example: Oxygen Gas molecules are 2 Oxygen atoms bonded together written O 2