2 The Man Behind the Table Dmitri Mendeleev1. Russian Chemist2. Organized the 1st Periodic Table3. In the mid-1800’s4. Only 63 known elements at that time5. Predicted existence of several unknown elements6. Element 101 is named after him
3 Organizing the Table Mendeleev’s Organization: 1. He put each elements information on a card.A. Atomic mass, density, color, melting pointB. Valence electrons (outer-shell)2. He saw a “periodic” pattern when arranged by atomic mass…
4 Mendeleev’s TableMendeleev’s table was designed so that the elements were arranged in order of increasing atomic mass.He said, “the properties of the elements were periodic functions of their atomic masses.”However, Mendeleev was sort-of wrong!
5 Today’s Periodic Table British scientist, Henry Moseley saw errors in Mendeleev’s table in 1914.Moseley rearranged the table by increasing atomic number (# of protons).Moseley’s table is the table that we use today!Henry G.J. MoseleyDetermined the atomic numbers of elements from their X-ray spectra (1914)Arranged elements by increasing atomic numberKilled in WW I at age 28(Battle of Gallipoli in Turkey)H.G.J. Moseley ( ) while doing post-doctoral work (with Ernest Rutherford) bombarded X-rays at atoms in increasing number and noted that the nuclear charge increased by 1 for each element. This gave him the idea to organize the elements by increasing atomic number.Periodic law – elements organized by increasing atomic number on periodic table (1913)In 1913, Moseley analyzed the frequencies of X -rays emitted by the elements and discovered that the underlying foundation of the order of the elements was atomic number, not atomic mass.Moseley hypothesized that the placement of each element in his series corresponded to its atomic number Z, which is the number of positive charges (protons) in its nucleus.Moseley- wavelengths in X-rays determined by the number of protons in the nucleus of the anode atoms- change anode, change wavelength
6 Review: Periodic Table GROUPS The columns of the Periodic Table are called groups (or families)Elements in a group/family have similar properties just like how your family members have similar traits!Each group/family has a name (like your last name)
7 Review: Periodic Table GROUPS The number of the group (in the ones place) indicates the number of valence electrons that atoms within that group have (or the number of the TALL column)Valence electrons are electrons located in the outermost energy level that play a role in bonding and reactivityThere are 18 groups on the Periodic TableOn p.11, number the GROUPS on your Periodic TableLabel them “Groups/Families” with an arrow showing which direction they go.
8 Review: Periodic Table PERIODS The rows of the Periodic Table are called periodsElements in a period have different properties!The periods follow a periodic patternPeriodic: occurring at regular intervals
9 Review: Periodic Table PERIODS The number of the period indicates the number of energy levels that atoms within that period haveThere are 7 periods on the Periodic Table (Helpful fact: “Periods” has 7 letters)On p.11, number the periods on your Periodic TableLabel them “Periods” with an arrow showing which direction they go.
11 Metals Good conductors of heat and electricity Usually solid at room temperatureException: Mercury is a liquid at room temperature. On p.11, outline Mercury (Hg) in blueMalleable and ductileLocated to the left of the stair-step line. On p.11 label the left half of the Periodic Table “Metals.”Exception: Hydrogen is not a metal, but is located to the left of the stair-step line.Tend to give up electrons in chemical reactions
15 Groups 3-12 : Transition Metals Lanthanide SeriesActinide Series
16 Lithium reacting with water Alkali MetalsGroup 1The most reactive of all metals (only need to lose one electron)Have 1 electron in their outer energy levelsLithium reacting with water
17 Magnesium reacting with HCl Alkaline Earth MetalsGroup 2Very reactiveHave 2 electrons in their outer energy levelsCalciumMagnesium reacting with HCl
18 Transition Metals/Elements Groups 3-12Inner Transition MetalsLanthanide SeriesAtomic numbers 58-71Named the lanthanide series because they follow LanthanumActinide SeriesAtomic numbersNamed actinide series because they follow ActiniumAll are radioactive and unstable
23 Nonmetals Poor conductors of heat and electricity Usually gases or brittle solids at room temperatureException: Bromine is a liquid at room temperature. On p.11, outline Bromine (Br) in blueOn p.11, outline all of the GASES in red. (H, He, N, O, F, Ne, Cl, Ar, Kr, Xe, Rn)Located to the right of the stair-step line. On p.11 label the right half of the Periodic Table “Nonmetals.”Exception: Hydrogen is a nonmetal, but is located to the left of the stair-step line.Tend to accept electrons in chemical reactions with metalsTend to share electrons in chemical reactions with other nonmetals