THE PERIODIC TABLE http://www. dayah THE PERIODIC TABLE http://www.dayah.com/periodic/Images/periodic table.png Mendeleev’s Periodic Table (Figure 6.3) Arranged elements into rows and columns Elements ordered by atomic mass.

THE PERIODIC TABLE Modern periodic tables (Figure 6.5) Also arrange elements into rows and columns. Elements are ordered by increasing atomic number

PERIODIC LAW There are 7 periods (rows) in the periodic table. Period 1 = 2 elements Period 2 = 8 elements Period 3 = 8 elements Period 4 = 18 elements Period 5 =18 elements Period 6 = 32 elements Period 7 = 24 elements Each period = principal energy level.

PERIODIC LAW Elements within a Group (column) have similar properties. The properties of elements within a period change as you move across a period from left to right. PERIODIC LAW STATES: when elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.

Metals, Nonmetals, Metalloids 80% of elements Good conductors of heat and electric current All are solids at room temperature (EXCEPT: mercury!) Ductile (drawn into wires) Most are malleable

Metals, Nonmetals, Metalloids Found in the upper right hand corner of the periodic table Most are gases at room temperature (i.e. oxygen and nitrogen) Poor conductors of heat and electric current (except carbon) Solid nonmetals tend to be brittle

Metals, Nonmetals, Metalloids Properties similar to both metals and nonmetals Depending on the conditions a metalloid may behave like a metal or a non metal.

Checkpoint Which of these sets of elements have similar physical and chemical properties? a. oxygen, nitrogen, carbon, boron b. strontium, magnesium, calcium, beryllium c. nitrogen, neon, nickel, niobium Identify each element as a metal, metalloid, or nonmetal. a. gold metal c. sulfur non metal b. silicon metalloid d.barium metal

Classifying Elements *** Put your name and date at the top! For helium, label the element symbol, element name, atomic number and the atomic mass. Label all groups and periods Color code (entire box) with key Metals Non metals Metalloids Gas Liquid Solid Indicate where to find: Alkali metals, alkaline earth metals, halogens, noble gases *** Put your name and date at the top!

The Representative Elements Groups IA through 7A. The valence electrons (electrons in the highest occupied energy level)= group number!

Transitional Elements Columns 3-12 (or Groups IB-VIIIB) Transition metals and inner transition metals Transition metals have e- in d orbitals (main body) Inner transition metals have e- in f orbitals (formerly known as rare earth metals)

Practice Problems Use figure 6.9 and Figure 6.12 (or the s,p,d,f handout) to write the electron configurations of the following elements. A. Carbon 1s2 2s2 2p2 B. Strontium 1s2 2s2 2p63s23p63d104s24p65s2 C. Vanadium 1s2 2s2 2p63s23p63d34s2

PERIODIC TRENDS Atomic Radius 1/2 the distance between the nuclei of two atoms of the same element when the atoms are joined. Measured in picometers(pm) there are one trillion (1012 pm in one meter) Decreases because # of protons increases therefore attractive forces are pulling in the e-’s . Increases because you are adding more energy levels.

IONS Ions-charged atoms due to the gain/loss of electrons Anion- ion with a negative (-) charge (nonmetals) Cation-ion with a positive (+) charge (metals) When compounds form, elements gain or lose e-’s to form ions in order to attain a stable noble gas configuration.

Ionization Energy Ionization Energy (IE) The amount of energy needed or absorbed to remove an electron from an atom. The further away an e- the less IE needed to remove the e-.( but also consider protons and electrons are increasing)

IONIC SIZE Anions (-) are larger than cations (+) due to taking e-’s away which reduces the radius. Among the anions and cations the trend is the same as atomic radius Decreases  Increases 

ELECTRONEGATIVITY Electronegativity (EN) The ability of an atom to attract itself the electrons when in a compound (bonded). Electrons shift toward the more EN atom

PERIODIC TREND SUMMARY

PRACTICE Atomic Radius--rank the following according to size from smallest to larger. Mg, Al, Ca Al < Mg < Ca S, Cl, S-2 Cl < S < S-2 Fe +2, Fe, Fe +3 Fe +3 < Fe +2 < Fe

PRACTICE Which element in each pair has a higher electronegativity value? Cl or F F C or N N Mg or Ne Mg As or Ca As