Atoms, Elements, and Molecules

Atoms Atoms are the building blocks of matter. They make up everything that we know. All matter is made of atoms. Made up of three smaller parts. Protons Neutrons Electrons

Atoms Nucleus 8 Protons 8 Neutrons Oxygen

Atoms Electrons Atomic Shell

Elements Matter made of only one type of atom is called an element. Element Name Atomic Number Element Symbol Mass Number

Elements Atomic Number: The number of protons in the nucleus of an atom. Mass Number: The number of protons and neutrons in the nucleus.

Elements: Substances made entirely from one type of atom.

Molecules A molecule is formed when two or more atoms join together chemically. H2O Water Molecular Oxygen O2 Methane CH4

Which of these is NOT a compound Compounds Which of these is NOT a compound A compound is a molecule that contains at least two different elements. All compounds are molecules not but not all molecules are compounds. H2O Water Methane CH4 Molecular Oxygen O2

Challenge: Covalent Bonding What you need to know: The elements on the periodic table have the same number of protons and electrons. Covalent bonds share electrons to fill an atoms valence shell. Valence Shells Holds the electrons of an atom. Octet Rule: An atom is most stable when its outermost shell is filled with electrons.

Challenge Number of electrons = 2n2 n = shell number

Challenge: CO2