Mendeleev Periodic table The periodic table arranges all the elements in groups according to their properties. Horizontal rows are called PERIODS Vertical columns are called GROUPS
Group or Family Runs Vertical Elements have the same properties. Group number can help determine the oxidation number. Tell the number of valence electrons.
H HeHe Li BeBe BCNOF NeNe NaNa MgMg AlSiPSClAr K CaCa FeFe Ni CuCu ZnZn Br KrKr AgAg I XeXe Pt AuAu HgHg The Periodic Table Fact 1: (Most important) All of the elements in the same group have similar PROPERTIES. This is how I thought of the periodic table in the first place. This is called PERIODICITY. E.g. consider the group 1 metals. They all: 1)Are soft 2)Can be easily cut with a knife 3)React with water
H HeHe Li BeBe BCNOF NeNe NaNa MgMg AlSiPSClAr K CaCa FeFe Ni CuCu ZnZn Br KrKr AgAg I XeXe Pt AuAu HgHg The Periodic Table Fact 2: Elements in the same group have the same number of electrons in the outer shell (this correspond to their group number) E.g. all group IA metals have __ electron in their outer shell These elements have __ electrons in their outer shell These elements have __ electrons in their outer shells
Electrons Negative charged particles found outside the nucleus. If atom is neutral – protons will equal electrons. Hydrogen atom
Oxidation Number Tells the number of electrons that an atom will lose or gain. (+) means the element is losing electrons. (-) means the element is gaining electrons.
Valence Electron The number of electrons in the outer energy level. What element is below? Helium
Lewis Dot Diagram Represents the number of valence electrons in an atom.
Period Horizontal Row Period number tells the number of energy levels in an atom.
Energy Level Area where the electrons are found orbiting outside the nucleus.
H HeHe Li BeBe BCNOF NeNe NaNa MgMg AlSiPSClAr K CaCa FeFe Ni CuCu ZnZn Br KrKr AgAg I XeXe Pt AuAu HgHg The Periodic Table Fact 3: Most of the elements are metals: These elements are metals Zig Zag line divides metals from non-metals These elements are non-metals Along the Zig Zag line is the metalloids.
Metals Tend to be (+) charged particles (cations). Properties: Luster (shiny), conduct heat and electricity. Malleable Ductile Loosely held valence electrons.
Alkali Metals Group IA Lose 1 electron Oxidation number (+1) Most active group
Alkaline Earth Metals Group IIA Lose 2 electrons Oxidation Number (+2)
Transition Elements Group B’s Most have varying oxidation numbers. Exceptions: Zn (+2) Cd (+2) Ag (+1)
Coinage metals Copper, Silver, Gold In 1934 the U.S. eliminated gold from it’s coins even though gold bullion is still stored at Fort Knox, KY. Silver was eliminated in 1971. Nickel and Zinc has been used to replace more costly elements.
Group IIIA- Boron Family Oxidation Number (+3) Loses 3 electrons
Group IVA – Carbon Family Oxidation Number (+4) or (-4) Loses or gains 4 electrons. Two exceptions: Tin (+2 and +4) and Lead (+2 and +4). Metals of this group are always positive.
Group VA- Nitrogen Family Gains 3 electrons. Oxidation number (-3)
Chalcogen Group VIA Gain 2 electrons Oxidation number -2 Many things that stink, contain sulfur (rotten eggs, garlic, skunks,etc.)
Metalloids Tend to have properties of both metals and nonmetals.
Nonmetals Non- Lustrous Poor conductors, Semiconductor - an element that does not conduct electricity as well as a metal Tightly held valence electrons
Halogens Group VIIA Gain 1 electron Oxidation Number (-1)
Group VIIIA – The Noble Gases He Ne Ar Kr Xe Rn
Noble Gases Group VIIIA All have 8 valence electrons, except He it only has 2. Oxidation Number 0 Filled outer energy level. So do not lose or gain electrons. Does not form bonds naturally. Referred to as the Inert gases.