Today in ScienceYou will Need:1)Pencil, Colored Pencils, Highlighters orMarkers2)Power Notes – Atomic Structure– 2page 3 sides-Bookshelf- Please Staple
Topic:Power Notes- AtomicStructureDo we understandeverything????
Democritus 400 BC • 1st idea of “atoms” Greece - stated that all matter is made up • Believed all matter is made of atoms. He also stated that atoms are up of tiny particles separated eternal and invisible and so small that they can’t be divided, by space and they entirely fill up the space they’re • Called particles “atomos” in which means indivisible.Lavoisier 1789 • Founder of modern chemistry France - provided the formula for the conservation of matter • 1st carefully controlled in chemical reactions, and also distinguished experiments providing between an element and a compound evidence to the Law of Conservation of Mass
Dalton 1766-1844 1st MODERN Atomic Theory England - formed the 1st 1.All matter made up of tiny atomic theory, which states that all matter is composed of indivisible particles called atoms tiny, indestructible particles called atoms that are all alike 2.Atoms of the same element and have the same atomic weight. have identical properties 3.Atoms of different elements have different properties 4.Atoms combine in a specific ratio to form compounds 5.A specific compound is always made up of atoms in a specific proportion.
Thomson 1897 Plum Pudding Model 1.Negative particles scrambled into the “dough” of the positive particles. England - discovered the electron and developed the plum- pudding model of the atom.Rutherford 1898 Gold Foil Experiment England - used the results of his gold-foil 1.Atoms are mostly empty experiment to state that all the mass of an space atom was in a small positively-charged 2.All the Mass of an atom is in ball at the center of the atom. the positively charged ball in the center of the structure.
Rutherford Continued• Top(RED): Expected results: alpha particles passing through the plum pudding model of the atom undisturbed. Bottom (YELLOW): Observed results: a small portion of the particles were deflected, indicating a small, concentrated positive charge. Note that the image is not to scale; in reality the nucleus is vastly smaller than the electron shell
Bohr 1922 Denmark - stated that “Planetary” atom model the electrons moved 1.Believed the atom structure was like our around the nucleus in successively large solar system orbits. He also presented the Bohr 2.Nucleus in the middle like the sun and atomic model which the electrons orbiting like the planets. stated that atoms absorb or emit radiation only when the electrons abruptly jump between allowed, or stationary, states. Schroedinger 1930 Wave Mechanic Model Austria - introduced the Shroedinger Equation, a 1.Planetary model was too specific wave equation that describes the form of the 2.Rather: electrons vibrate around the probability waves that govern the motion of outside of the nucleus- can only small particles and how these waves are altered predict where they are most like to be by external influences. 3.QUARKS – protons, neutrons and electrons made up of some of these smaller particles. 4.http://library.thinkquest.org/05aug/01087/quarks.html
Basic Atomic Structure Today scientist agree on the three basic subatomic particles that make up all atoms.Bohr Model for Lithium(not to scale) Electron = 3 P= 3 + N = 3 0Where is most of the mass in the NUCLEUSAtom?Where is most of the volume in the Outside the Nucleus; ElectronAtom? Cloud
Nucleus • Contains protons(+) and Neutrons (0) • Holds most of the mass of the atom • Very small compared to the entire size of the atom • Most dense part of the atomElectron • Negatively charged subatomic particle • Found outside the nucleus in the electron cloud • Smallest particle; mass = 1/1836th of the atom
• Positively charged subatomic particle Proton • Found in the nucleus • Mass = 1 amu (atomic mass unit) • # of protons in an atom IDENTIFIES the atom (which element) • Each element has its own unique # of protons- change the proton count: change the element • # of protons in the nucleus of an atom called the atomic number Neutron • Zero charge • Mass = 1 amu • Do NOT affect the identity of the atom • Found in the nucleus • Same atom of an element can have varying amounts of neutrons (isotope) • Adding the total number of protons & neutrons = Atomic Mass Numberhttp://www.sawyerscience.com/Units/unit2/atoms_compounds.html
• Atomic Number : • # of protons 3 • # of electrons if atom is neutrally Li • charged Chemical Symbol: Lithium • Element abbreviation 6.9 • Some based on Latin names • Element Name: • There in case you forget • Atomic Mass: • Sum of the particles in the nucleus (protons & neutrons) • Can change with isotopes of the same element • Represents an AVERAGE MASSIsotope Same # of protons (same element); different # of neutronsIon Charged particle; electrons vary
Homework 1)Complete Power Notes– Due Monday at the end of the period.