Objective Introduce Elements A Elements 1 All things

Objective: Introduce Elements A) Elements 1) All things are composed of atoms. 2) The elements include 112 different types of atoms, 88 occur naturally. 3) 90% of all atoms are hydrogen. 4) Hydrogen atoms are the remnant of stars that exploded. 5) Complex atoms are formed in stars.

Objective: Introduce Elements A) Elements (Cont. ) 6) Living things are made of H, N, O, C. 7) Atoms are ageless. 8) Atoms are smaller than visible light. 9) Brownian motion 10) Atoms consist of protons, neutrons, and electrons.

Objective: To see how the Thompson Experiment determined the mass and charge of an electron. B) Thomson Experiment. 1) Vacuum tube was invented near the time that Benjamin Franklin began experiments with electricity, a. k. a. Cathode Ray Tube. 2) Rays were seen when a vacuum tube was connected to electrical current on the ends. 3) The rays would bend when an electric field was placed nearby. The bending was based on the mass of the particles and the charge. 4) Later determined that the particles were electrons.

Objective: To determine how the Millikan Experiment determined the mass of an electron. C) Millikan Experiment. 1) Sprayed tiny particles of oil into an electric field. 2) The particles would float and because they did he was able to determine their mass and charge. 3) Later determined that the particles were electrons.

D) The electron. 1) Mass: 9. 1 * 10 -31 kg 2) Negatively charged 3) Located on the outer edges of an atom. 4) Electrons helped determine the properties of the material a) chemical reactivity b) physical properties (taste, color)

H) Electromagnetic Spectrum. 1) Energy released as waves makes up the electromagnetic spectrum. 2) Electrons that move closer to the nucleus release energy in the form of waves. 3) Electrons require energy to move away from the nucleus of an atom. 4) The different amounts of energy are based on how far or close they move.

H) Electromagnetic Spectrum Photon energy: Q 1 - Q 2 Lower energy state: Q 2 Higher energy state: Q 1

H) Electromagnetic Spectrum 1) Waves

H) Electromagnetic Spectrum. Low Energy High Energy (See handout)

H) Electromagnetic Spectrum: 6) Visable light portion

H) Electromagnetic Spectrum 5) Comparisons (continued)

H) Electromagnetic Spectrum 5) Comparisons

I) Atomic Spectrum. 1) The electrons in each atom are arranged differently. 2) When the electrons move they emit energy in the form of different colors of light. 3) Each atom has unique color combination.

Sun Light Spectrum vs. Hydrogen Spectrum Light from the sun or a light bulb has a continuous spectrum Light from Hydrogen gas has a discrete (non-continuous) spectrum

I) Atomic Spectrum (cont. ) Each shell can be represented as a layer that an electron can fall.

Examples of emissions from specific atoms

The Periodic Table The periodic table is read from top to bottom, left to right, as atomic number increases: 1=H, 2=He, 3=Li, 4=Be, 5=B, 6=C, and so on.

The Periodic Table alkali earths Elements in columns (groups) have similar outer-electron configurations, and so tend to behave similarly. transition metals alkalis halogens rare earths noble gases actinides