Structure of an Atom What makes up an

Structure of an Atom 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 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

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: ØProtons - positively charged particles in the nucleus of the atom ØNeutrons - + 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 Ø 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 Maximum of 50 electrons Maximum of 8 electrons Nucleus Maximum of 18 electrons Maximum of 32 electrons

Outer Structure of an Atom ●valence electrons are in the outermost energy level and are the electrons involved in bonding Øvalence is the number of bonds an atom can form Ø 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. *****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 # of protons Atomic mass 6 C carbon 12. 0 Atom’s symbol Atom’s name

Decoding Atom Information cont: # of protons = # of electrons 6 C carbon Atomic mass = # of protons plus the # of neutrons 12. 0