Atomic Theory John Dalton Four Part Theory adopted as basis for the Modern Atomic Theory Four Part Theory adopted as basis for the Modern Atomic Theory 1.All things are made of atoms 2.Similar atoms are similar and different atoms are different 3.Atoms combine to form molecules 4.Chemical reactions do not alter atoms

Electrons J.J. Thomson English physicist English physicist Worked on electricity, magnetism, and charged particles Worked on electricity, magnetism, and charged particles Discovered ELECTRON Discovered ELECTRON

Electrons J.J. Thomson Used a cathode ray tube and experimented with the beam of energy. Used a cathode ray tube and experimented with the beam of energy. Based on deflection with magnets and electricity, he assumed the beam was made of negative particles. Based on deflection with magnets and electricity, he assumed the beam was made of negative particles. Discovered electron Discovered electron

Electrons J.J. Thomson Plum Pudding Model of Atom Plum Pudding Model of Atom Electrons as discrete particles Electrons as discrete particles Remaining mass an unorganized glob. Remaining mass an unorganized glob.

Nucleus Ernest Rutherford Used alpha particles (Helium atoms) fired at a piece of gold foil. Used alpha particles (Helium atoms) fired at a piece of gold foil. Deflections of the particles made him assume that there was a massive particle at the center of the atom. Deflections of the particles made him assume that there was a massive particle at the center of the atom. Discovered Nucleus Discovered Nucleus

Gold Foil Experiment

Neutron James Chadwick Calculated the mass of similar atoms. Calculated the mass of similar atoms. Recognized isotopes. Recognized isotopes. First to recognize the extra mass in the nucleus was a neutral particle…Neutrons First to recognize the extra mass in the nucleus was a neutral particle…Neutrons

Splitting the Atom Lise Meitner Calculated the energy in “Binding Energy” in the nucleus. Calculated the energy in “Binding Energy” in the nucleus. First to recognize the disintegration of a nucleus First to recognize the disintegration of a nucleus

Radiation Andre Becquerel Discovered radiation Discovered radiation Marie Curie Early research in radiation. Early research in radiation.

Ions and Isotopes Three particles in the atom ProtonNeutronElectron ProtonNeutronElectron ChargedNeutralCharged Has MassHas MassNo Mass 1 AMU 1 AMU 0 AMU 1 AMU 1 AMU 0 AMU

Ions Ions have Three Characteristics 1. Ions are charged particles 2. Protons not equal to electrons 3. Can be positive or negative

Ions Calculate the Charge A Carbon atom with 6 protons, six neutrons and six electrons (6 protons x (+1)) = +6 (6 neutrons x (0)) = 0 (6 electrons x (-1)) = -6 Sum = 0 (no charge)

Ions Calculate the Charge A Carbon atom with 6 protons, six neutrons and four electrons (6 protons x (+1)) = +6 (6 neutrons x (0)) = 0 (4 electrons x (-1)) = -4 Charge = +2

Isotopes Isotopes are all about Mass Compare protons and neutrons If protons and neutrons are NOT equal, then the atom is an isotope.

Isotopes Calculate the Mass A Carbon atom with 6 protons, 6 neutrons and 4 electrons (6 protons x (1 AMU)) = 6 AMU (6 neutrons x (1 AMU)) = 6 AMU (4 electrons x (0 AMU)) = 0 AMU Mass = 12 AMU

Isotope Notation Ni Mass = Protons + Neutrons Atomic Number or Number of Protons Charge Element

Ions and Isotopes F K Ni N As Ar 18 36

Ions and Isotopes B V Si Cl Cu Kr 36 72

Chemistry The Mole

Mole The mole is a term to describe quantity. 1 dozen = 12 things 1 gross = 12 dozen = 144 things 1 mole = 602,000,000,000,000,000,000,000 things 6.02 x things

Mole The mass of one mole of an element is the atomic mass. 1 mole of Carbon = 12 grams 1 mole of Sodium = 23 grams 1 mole of Carbon atoms is 6.02 x atoms 1 mole of Sodium atoms is 6.02 x atoms One is a measure of “mass” The other is a measure of “how many”

The Mole F What is the mass of 2 moles of this element? How many atoms are present in 2 moles of this element? Is this atom an ion an isotope both or neither?

Periodic Table Objectives Element Names and Symbols Element Names and Symbols Periodic Table Geography Periodic Table Geography Characteristics of Major Groups Characteristics of Major Groups

Periodic Table Dimitri Mendeleev Organized the Periodic Table Organized the Periodic Table Made predictions about the elements yet to be discovered Made predictions about the elements yet to be discovered

Periodic Table

Alkali Metals Alkali Metals: Highly reactive elements that combine with many nonmetals to form ionic solids (salts). They also form compounds with oxygen that dissolve in water to create solutions that are strongly alkaline.

Alkaline Earth Metals Alkaline Earth Metals: Very reactive elements that form ionic compounds with nonmetals. Many of their oxygen compounds are found in deposits in the ground.

Transition Metals Transition Metals: Generally less reactive than the alkali and alkaline earth metals, these elements vary in physical and chemical properties. Many form important alloys with one another and other metals. Several of the transition elements can form more than one positive ion. For example, iron can form more than one ion, Fe 2+ and Fe 3+.

Halogens Halogens: Reactive elements that form compounds known as halides. Several halogens including chlorine, fluorine and iodine, have important applications in everyday life.

Noble Gases Noble Gases: Elements are generally not reactive; however, the heavier noble gases can react with a few halogens. These elements have generally complete electron shells. They are gases at very low and very high temperatures.

Metalloids Metalloids: Elements that display characteristics of both metals and non-metals. They are only partial conductors of electricity and are therefore also known as semiconductors.

Non-Metals Non-Metals: Elements that do not display characteristics of metals. They are not shiny, they do not conduct electricity, and they are not malleable

Metals: Elements that display characteristics of metals. They are shiny, they conduct electricity, and they are malleable