Mendeleev In 1869, Dmitri Ivanovitch Mendeléev created the first accepted version of the periodic table. He arranged elements according to their atomic mass, and as he did, he found that the families had similar chemical properties.  He left blank spaces open to add the new elements he predicted would occur. 

Arranging the Elements Mendeleev arranged all the elements then known about, by their atomic mass. H=1 Li=7? Be=9.4 B=11? C=12 N=14 O=16 F=19? Na=23 Mg=24 Al=27.4 Si=28 P=31 S=32 Cl=35.5 K=39 Ca=40 Er=56 Ni=Co=59 Yt=60 Cu=63.4 Zn=65.8 As=75 In=75.6 Se=79.4 Br=80 Rb=85.4 Sr=87.6 Ce=92 La=94 Di=95 Th=118?

Arranging the Elements Ni=Co=59 H=1 Cu=63.4 Be=9.4 Mg=24 Zn=65.8 B=11 Al=27.4 ?=68 C=12 Si=28 ?=70 N=14 P=31 As=75 O=16 S=32 Se=79.4 F=19 Cl=35.5 Br=80 Li=7 Na=23 K=39 Rb=85.4 Ca=40 Sr=87.6 ?=45 Ce=92 ?Er=56 La=94 ?Yt=60 Di=95 ?In=75.6 Th=118? Mendeleev noticed that the elements properties repeated. Notice the table is flipped 90 degrees

Mendeleev arranged the elements much like you would lay out a deck of cards. The cards are arranged by number (like atomic mass) and by properties (suit). Doing so allowed him to see that elements were missing and allowed him to predict their properties. Mendeleev arranged the elements much like you would lay out a deck of cards. The cards are arranged by number (like atomic mass) and by properties (suit). Doing so allowed him to see that elements were missing and allowed him to predict their properties.

Mendeleev’s 1869 Periodic Table

Periodic table design is universal

The periodic table is universal in its design The periodic table is universal in its design. Scientists can understand and use periodic tables even if they are in a different language. Names may be different but the symbols and numbers are the same.

Japanese Periodic Table

Russian

Universal Design The Periodic Table is standard design that can be read and understand worldwide.

O Si Hg What’s in a square? Periodic tables often include the following information: Atomic number Symbol Name Atomic mass Type of element State of matter at room temperature 8 O Oxygen 16.0 14 Si Silicon 28.1 80 Hg Mercury 200.6

Element Classifications Metals Metalloids Nonmetals

Group/Family Period Group/Family- Elements in a column. Each column contains elements with similar properties. To remember direction of groups realize the last 2 letters of group spells “up” Periods- These are elements in a horizontal row. These elements differ, and the properties change in a regular pattern.

Groups Periods Columns of elements are called groups or families. Elements in each family have similar but not identical properties. For example, lithium (Li), sodium (Na), potassium (K), and other members of group 1 are soft, reactive, shiny metals. Elements in a family have the same number of valence electrons. Periods Horizontal rows of elements are called periods. Elements in a period are not alike in properties. The properties change greatly across the row. The first element in a period is always an extremely active metal. The last element in a period, is always an unreactive gas.

The Extended Periodic Table The 2 series on the bottom fit in group 3. They were pulled out to make a more compact table This shows how the Periodic table is arranged with the Lanthanides and Actinides where they fit in the main table.

Periodic Trends

Reactivity Trends

Relative Atomic Radii