Topic: Structure of an Atom Essential Questions: What makes up an atom? What is inside the atom?

What Is an Atom? Atom  building blocks of matter.  have a nucleus surrounded by an electron cloud/Energy levels/Rings Atoms are composed of smaller subatomic particles in an atom. A.) proton B.) neutron C.) electron. Each element is composed of one type of atom and can not be broken down into a simpler substance

Structure of an atom

Inner Structure of an Atom Nucleus - Small, dense, positively charged center of the atom which contains most of the atom’s mass The nucleus contains subatomic particles have certain characteristics: Protons - positively charged particles in the nucleus of the atom + Neutrons - particles in the nucleus that have no charge but contribute to the atom’s mass NEUTRAL 0

Outer Structure of an Atom Electron cloud - an area encircling the nucleus where electrons are likely to be found The cloud contains energy levels electrons are negatively charged -particles located in specific energy levels

Outer Structure of an Atom Energy levels completely surround the nucleus Maximum of 2 electrons Nucleus Maximum of 8 electrons Maximum of 18 electrons Maximum of 32 electrons Maximum of 50 electrons

Outer Structure of an Atom Valence electrons  are found in the outermost energy level (LAST SHELL)  involved in Chemical bonding valence is the number of bonds an atom can form an atom is most stable when its outermost energy level is full =8 electrons

Atom Characteristics Atomic Number  the number of protons in the nucleus of that atom. Neutral atom the number of protons (+) equals the number of electrons (-) Atomic mass is the mass of the protons plus the mass of the neutrons

Decoding Atom Information carbon 6 12.0 # of protons Atom’s symbol Atom’s name Atomic mass

Decoding Atom Information cont: # of protons = # of electrons 6 C carbon Atomic mass = # of protons plus the # of neutrons 12.0