HISTORY OF THE PERIODIC TABLE NOTES

Organization of the Periodic Table The _periodic_ _table_ is defined as an organization of the _elements_ in order of increasing _atomic_ _number_ and grouped according to similar _chemical___ properties and similar _electron_ arrangements. Organization of the Periodic Table

Dmitri Mendeleev was a _Russian____ scientist who set up the first periodic table in the __19th____century. Using Mendeleev’s system elements with similar _physical_ and _chemical_ properties fell into families or groups. In the beginning…

Mendeleev’s Period Table Organized by mass number Mendeleev’s Period Table

Periodic table is made up of _families_, which are the _vertical_ columns. _Families_ are a group of elements that share the same _chemical_ properties and the same number of _valence_ electrons. Groups or Families

The _horizontal_ rows on the periodic table are called _periods_. Elements found on the same _period_, share the same number of _energy_ levels found in the electron cloud. Elements on the periodic table are identified by three things _chemical symbol_, _atomic_ number, and _atomic_ mass. Periods

Metals Example: Al Metals lose electrons and have a positive charge Most metals are solids except for Mercury (Hg) is a liquid Properties of Metals luster (are shiny) malleable (bendable) ductile (can be stretched into a wire) conduct electricity Francium (bottom left corner) is the most reactive metal Metals Example: Al

Metalloids Example: Si Lose or gain electrons to become stable All solids Some metalloids like Silicon have luster but others like arsenic do not Some are malleable and ductile Some conduct electricity Metalloids are not very reactive because they need to gain or lose a lot of electrons Metalloids Example: Si

Nonmetals Example: S Gain electrons and have a negative charge All states of matter are represented Bromine- liquid Iodine- solid Xenon- gas No luster, malleability, or ductility Poor conductors of heat and electricity Fluorine (top right) is the most reactive nonmetal Noble Gases are completely unreactive Nonmetals Example: S

Families / Groups Alkali Metals Noble Gases Boron Group Oxygen Group 1 1 18 8 Group Valence e- Period 2 13 14 15 16 17 3 4 5 6 7 1 2 3 4 5 6 7 Alkaline Earth Metals Alkali Metals Noble Gases Boron Group Nitrogen Group Oxygen Group Halogens Carbon Group Transition Metals 3 4 5 6 7 8 9 10 11 12 Lanthanide Series Actinide Series 6 7 Families / Groups

Groups are vertical columns Periods represent horizontal rows Elements in the same family share the same number of valence electrons. Families

Families Hydrogen belongs to NO family: ***It is in group one because it has one valence electron but it is not a metal and is not basic. Alkali means basic. Be and Sr belong to the Alkaline Earth Metals family. Circle the element that belongs to the transition metal family: Rn, W, U, Ne, Sn Families

Charges

Charges Ions: atoms that form a CHARGE by losing or gaining electrons Oxidation Number/Charge: the number of electrons GAINED or LOST in an atom. Positive Ions: are called CATIONS; they lose their valence electrons Negative Ions: are called ANIONS; they gain e- in order to have a total of 8 valence electrons. Charges

When ions are formed, atoms can only become stable by GIVING or RECEIVING electrons with other atoms. Compounds: two or more atoms BONDED together by the VALENCE SHELL of their atoms. Charges

Ionic Bonds: a bond that TRANSFER electrons; a bond between METAL and NON- METAL. Covalent Bonds: a bond that SHARE electrons; a bond formed between NON- METAL and NON-METAL. Metallic Bonds: a sea of ELECTRONS in the metals atoms that gives metals its luster, malleability, ductility, and conductivity. This is not a TRUE bond, but it allows molten metal to form ALLOY (metal solutions), like brass. Charges

Reactivity F Metal Reactivity Decreases Non-Metal Reactivity Increases Non-Metal Reactivity Decreas Metal Reactivity Increases Fr Reactivity

Arrange the following elements to increasing metal reactivity: Ca, Sr, Ba Arrange the following elements to increasing non-metal reactivity: As, P, N Arrange the following elements to increasing metal reactivity: Ni, Co, Fe Arrange the following elements to increasing non-metal reactivity: C, O, F Arrange the following element to decreasing metal reactivity: K, Na, Li Reactivity

Atomic Radii

Atomic Radii The size of the atom The atomic radii increases down a group because it is adding extra energy levels The atomic radii decreases across a period because the atom does not want to lose electrons so it attracts them close to the positive nucleus (the force of attraction increases) Atomic Radii

Ionization Energy

Ionization Energy The energy needed to remove an electron As you move down a group the ionization energy decreases because the electrons are so far from the nucleus they are not held tightly to the atom and it takes little energy to remove them As you move across a period ionization energy increases because the atom does not want to lose electrons so it holds the electrons tighter which takes more energy to remove them Ionization Energy

Electronegativity

Electronegativity The ability of an atom to attract electrons Electronegativity decreases down a group because the levels of electrons shield the positive nucleus from being able to attract additional electrons Electronegativity increases across a period because the atoms need to gain electrons to become stable Electronegativity