THE PERIODIC TABLEhttp://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

• Metals• 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

• Nonmetals• 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

• 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• 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