9/9/20151 Periodic Table The Basics Chemistry Mrs. Sousa & Mr. Pickin

9/9/20152 Introduction This presentation will give you all the information you need to know about the basic organization of the periodic table

9/9/20153 Origin The periodic table was first devised by Dmitiri Mendeleev in Russia in 1869 Based on the “Periodic Law” which states that the properties of the elements repeat periodically

9/9/20154 Basics Elements listed by increasing atomic number (Unique for each element) (thus properties) Atomic number is the number of protons contained in the nucleus of an atom of an element

9/9/20155 Major Divisions in Table Metals (<4 valence electrons) form + ions (cations). Ionic bonds Non-metals (>4 valence electrons) form - ions (anions). Covalent bonds Metalloids (semi-metals) Separated by zig-zag line Image

9/9/20156 Periods Horizontal (across) rows are called periods. Properties of elements change across the period. 7 periods (maximum) Period number is the number of energy levels each element contains in that row (quantum # n value as well)

9/9/20157 Groups/Families Either term acceptable Vertical columns 18 families Numbered from left to right Members of the same family have very similar chemical and physical properties. Atoms increase in size as you get lower in a group.

9/9/20158 Representative Families. Representative families are 1,2,13, 14,15,16,17,18  Ones place is the number of valence electrons  In other words- for put your finger over the #1!  Ex. Family 16 has 6 valence electrons  Valence electrons are those in the outer energy level – they are used for bonding and come from the s & p orbital space  Noble Gases (group #18) all have 8 valence electrons.  Exception to the octet rule: He (helium) has 2 valence electrons

9/9/20159 Common Names  1-Alkali metals (most active metals)  2-Alkaline earth metals  16-Chalcogens 17-Halogens (most active non-metals) 18- Noble gases (not reactive) 3-12 Transition metals (1 or 2 valence electrons) Lanthanide series (AN 57-71) Actinide series (AN )

9/9/ Regions of the Periodic Table

9/9/ Group 1: Alkali Metals Cutting sodium metal Reaction of potassium + H 2 O

9/9/ Magnesium Magnesium oxide Group 2: Alkaline Earth Metals

9/9/ Group 17: The Halogens (salt makers) F, Cl, Br, I, At

9/9/ Group 18: The Noble (Inert) Gases He, Ne, Ar, Kr, Xe, Rn Lighter than air balloons “Neon” signs Very Unreactive because they have full electron levels XeOF 4

9/9/ Transition Metals (elements) Families 3-12 Lanthanide series click Lanthanide seriesclick Actinide series Multivalent – can have 1, 2, 3 valence electrons – depending on what other atoms they are bonding with.

9/9/ Transition Elements Lanthanides and actinides Iron in air gives iron(III) oxide

9/9/ s, p, d, f blocks

9/9/ Atomic Radius (size) The trend is that: Atoms get smaller going across a period (Noble gases are the exception) Atoms get larger going down a family

9/9/ Atomic Radius (cont.)

9/9/ Atomic Radius (cont)

9/9/ Ionization Energy (IE) The amount of energy necessary to remove one or more electrons from an atom in its gaseous state Generally:  Metals have low IE  Non-metals have high IE

9/9/ Ionization Energy (IE) IE increases across a period IE decreases down a family

9/9/ Electronegativity (EN) The tendency of an atom to attract electrons (affinity for electrons) An atom's electronegativity is affected by both the positive charge in the nucleus and the distance that its valence electrons reside from the charged nucleus. The higher the associated electronegativity number, the more an element or compound attracts electrons towards it. Range of EN’s for the elements is 0.7 (Fr) to 4.0 (F) Trend:  EN increases across a period and decreases down a family

9/9/ Electronegativity (EN) Trend

9/9/ Electronegativity (cont.)

9/9/ Electron Affinity The energy released when an electron is added to a neutral atom. (exothermic process) for the first added electron the process is exothermic