Group NamesAlkali MetalsAlkaline Earth MetalsHalogensNoble Gases
Characteristics of Metallic Elements•Metals have a shiny metallic luster.•Metals conduct heat well and conduct electric currents in the solid form.•Metals are malleable. –For example, gold, Au, can be hammered into very thin sheets without breaking.
Metals, Nonmetals, and Metalloids
Classification of Elements
Solid, Liquid, and Gaseous Elements
Atoms• Tiny…about 10-10m–If the atoms in your body were 1 in. in diameter, you’d bump your head on the moon. • Huge number of atoms in even a small sample of an element–1/2 carat diamond has 5 ×1021atoms…if lined up, would stretch to the sun.
Particles in the Atom• Neutron (n)0 charge 1.00867 u in nucleus• Proton (p)+1 charge 1.00728 u in nucleus• Electron (e−)−1 charge 0.000549 u outside nucleus
Electron Cloud for Hydrogen Atom
The Electron“If I seem unusually clear to you, you must have misunderstood what I said.”Alan Greenspan, Head of the Federal Reserve Board“It is probably as meaningless to discuss how much room an electron takes up as to discuss how much room a fear, an anxiety, or an uncertainty takes up.” Sir James Hopwood Jeans, English mathematician, physicist and astronomer (1877-1946)
Wave Diffraction Patterns
Effect on Chemical Changes• Electrons–Can be gained, lost, or shared…actively participate in chemical changes–Affect other atoms through their -1 charge• Protons–Affect other atoms through their +1 charge–Determine the number of electrons in uncharged atoms• Neutrons–No charge…no effect outside the atom and no direct effect on the number of electrons.
Ions•Ionsare charged particles due to a loss or gain of electrons.•When particles lose one or more electrons, leaving them with a positive overall charge, they become cations. •When particles gain one or more electrons, leaving them with a negative overall charge, they become anions.
Isotopes of Hydrogen
Isotopes•Isotopesare atoms with the same atomic number but different mass numbers. •Isotopesare atoms with the same number of protons and electrons in the uncharged atom but different numbers of neutrons. •Isotopesare atoms of the same element with different masses.
Tin has ten natural isotopes.
Possible Discovery of Elements 113 and 115•Dubna, Russia•Dubna’s Joint Institute for Nuclear Research and Lawrence Livermore National Laboratory•Bombarded a target enriched in americium, 243Am, with calcium atoms, 48Ca.
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