1. Today in Science You will Need: 1)Pencil, Colored Pencils, Highlighters or Markers 2)Power Notes – Atomic Structure– 2 page 4 sides-Bookshelf- Please Staple

2. Topic: Power Notes- Atomic Structure Do we understand everything???? Name Date Period The concept of “atoms” is believed to have originated in ancient Greece with Democritus supporting the idea that all matter is made up of tiny particles. It has taken several hundred years to understand what we know about the atom today.. *NOT EVEN CLOSE!

3. Democritus 400 BC Lavoisier 1789 1 st idea of “atoms” Believed all matter is made up of tiny particles separated by space Named particles “atomos” which means indivisible. Founder of modern chemistry 1 st carefully controlled experiments providing evidence to the Law of Conservation of Mass France - provided the formula for the conservation of matter in chemical reactions, and also distinguished between an element and a compound Greece - stated that all matter is made up of atoms. He also stated that atoms are eternal and invisible and so small that they can’t be divided, and they entirely fill up the space they’re in

4. Dalton 1766-18441 st MODERN Atomic Theory 1.All matter made up of tiny indivisible particles called atoms 2.Atoms of the same element 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. England - formed the 1 st atomic theory, which states that all matter is composed of tiny, indestructible particles called atoms that are all alike and have the same atomic weight.

5. Thomson 1897 Rutherford 1898 Plum Pudding Model 1.Negative particles scrambled into the “dough” of the positive particles. Gold Foil Experiment 1.Atoms are mostly empty space 2.All the Mass of an atom is in the positively charged ball in the center of the structure. England - discovered the electron and developed the plum- pudding model of the atom. England - used the results of his gold-foil experiment to state that all the mass of an atom was in a small positively-charged ball at the center of the atom.

6. Bohr 1922 Schrödinger (Schroedinger ) 1930 “Planetary” atom model 1.Believed the atom structure was like our solar system: nucleus in the middle like the sun and the electrons orbiting like the planets. Wave Mechanic Model 1.Planetary model was too specific 2.Rather: electrons vibrate around the outside of the nucleus- can only predict where they are most like to be 3.QUARKS – protons, neutrons and electrons made up of some of these smaller particles. 4.http://library.thinkquest.org/05aug/01087/quarks.htmlhttp://library.thinkquest.org/05aug/01087/quarks.html Denmark - stated that the electrons moved around the nucleus in successively large orbits. He also presented the Bohr atomic model which stated that atoms absorb or emit radiation only when the electrons abruptly jump between allowed, or stationary, states. Austria - introduced the Shroedinger Equation, a wave equation that describes the form of the probability waves that govern the motion of small particles and how these waves are altered by external influences.

7. Basic Atomic Structure Bohr Model for Lithium (not to scale) Where is most of the mass in the Atom? Where is most of the volume in the Atom? Today scientists agree on the three basic subatomic particles that make up all atoms. P= 3 + N = 3 0 Electron = 3 NUCLEUS Outside the Nucleus; Electron Cloud

8. Nucleus Electron 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 atom Negatively charged subatomic particle Found outside the nucleus in the electron cloud Smallest particle; mass = 1/1836 th of the atom

9. Proton Neutron Positively charged subatomic particle Found in the nucleus Mass = 1 amu (atomic mass unit) # of protons in an atom IDENTIFIES the atom (which element) # of protons in the nucleus of an atom called the atomic number 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 Number http://www.sawyerscience.com/Units/unit2/atoms_compounds.html

10. All atoms found on the Periodic Table are Isotope Hydrogen has 3 natural occurring ISOTOPES: Protium, Deuterium and Tritium Neutral – same # of protons(+) and # of electrons(-) Atoms of the same element with same number of protons and different number of neutrons. nucleus Protium Tritium Deuterium All are HYDROGEN because all have 1 proton. Proton Neutron

11. Atomic MASS IONS REVIEW & REFLECT On the Periodic Table represents a weighted average of the mass of all naturally occurring isotopes of each element. (based on mass and abundance of each isotope). When atoms gain or lose electrons they become charged. (number of protons (+) and electrons (-) particles are NOT EQUAL) + -

12. Coloring the Periodic Table *Textbook pg 196-197 – Use the key Outline each box in the following way: 1.Metalloids – in BLUE 2.Nonmetals – in ORANGE 3.Metals – in GREEN

13. Homework 1)Power Notes– Due by Friday (There is time to work in class tomorrow) Do You see HOW the periodic table and the Atomic Structure are RELATED?