Presentation on theme: "Components of the Atom Nucleus: Nuclear Forces:"— Presentation transcript:
1 Components of the Atom Nucleus: Nuclear Forces: Small densely packed area located at the center of the atomNuclear Forces:Forces that allow protons and neutrons to exist close together in the nucleusElectron Cloud (orbitals)The large volume area that surrounds the nucleusSubatomic particlesParticles that make up the atomQuantity of these parts determine an element’s chemical/physical properties
2 Subatomic Particles Particle Charge Symbol Location Grams AMU* Proton Positivep+Nucleus1.673e-241NeutronNeutraln01.675e-24ElectronNegativee-Cloud9.11e-28* AMU = atomic mass unit
3 Characteristics of Atoms All matter is composed of atomsAtoms of one element differ in properties from atoms of another elementAtoms are neutral (p+ = e-)Atoms are mostly made of empty space.
4 Element Symbols12Mass NumberC6Atomic NumberC-12Mass Number
6 Difference between an Atom, Ion, and Isotope Charged particles (positive or negative)# of electrons change (p+ ≠ e-)Isotope:# of neutrons changeMasses are different since the # of neutrons are different** If the # of protons change, the element changes **
7 Isotopes Where to find the mass number of isotopes: Information will be given either 3 waysName: carbon-14 or C-14Symbol: 14CAdding given # no to p+ (or atomic #)The Atomic Mass of an Isotope will be given. It can not be taken from the periodic table.
8 Atomic MassesThe weighted average of all the isotopes masses known for an elementMasses found on periodic table are atomic massesAll elements have isotopes: some are radioactiveWhat you are given when trying to calculate atomic massEach known isotope and it’s atomic massThe percent abundance (how often it occurs) for each element
9 Atomic Masses The atomic mass is 27.9 amu Calculate the atomic mass of Si based on the following isotopes of Silicon:Si-28 Mass: %Si-29 Mass: %Si-22 Mass: %1) Multiple the mass of each isotope by the abundanceNote: the percent must be in decimal form2) Add the products above to find the atomic massThe atomic mass is 27.9 amu