chem unit3

Element TimelineAntiquity: Au, Ag, Cu, Fe, Pb, Sn, Hg, C, S

Before 1735: As, P, Sb, Zn

1735 – 1745 Co, Pt

1745 – 1755: Ni, Bi

1765 – 1775: H, O, N, Cl, Mn

1775 – 1795: Mo, W, Te, U, Sr, Ti, Y

1795 – 1805 : V, Cr, Be, Nb, Ta, Ce, Pd, Os, Rh, Ir

1805 – 1815: Na, K, Ba, Ca, Mg, I, B

Dobereiner’s Triads

7 + 39 = 23 2

For Li, Na and K

deChantcourtois’ Spirals

Newlands’ Octaves

Mendeleev (1869)

Lothar Meyer

Mendeleev’s Gaps

Henry Moseley

Organized according to atomic number rather than atomic mass

Periodic Table

Periodic Table

Periodic Table Families

Alkali Metals

3 electrons

11 electrons

19 electrons

37 electrons

55 electrons

87 electrons

Alkali Metals

1s2 2s1

1s22s22p6 3s1

1s22s22p63s23p6 4s1

1s22s22p63s23p64s23d104p6 5s1

1s22s22p63s23p64s23d104p65s24d105p6 6s1

1s22s22p63s23p64s23d104p65s24d105p66s24f145d1056p6 7s1

Alkaline Earth Elements

1s2 2s2

1s22s22p6 3s2

1s22s22p63s23p6 4s2

1s22s22p63s23p64s23d104p6 5s2

1s22s22p63s23p64s23d104p65s24d105p6 6s2

1s22s22p63s23p64s23d104p65s24d105p66s24f145d1056

p6 7s2

Noble Gases

1s2

1s22s22p6

1s22s22p63s23p6

1s22s22p63s23p64s23d104p6

1s22s22p63s23p64s23d104p65s24d105p6

Valence electrons

• Electrons in outermost electron orbital

Halogens

Chalcogens

Blocks

S block - Filling available s orbitalsP block - Filling available p orbitalsD block – Filling 3d, 4d, 5d and 6d orbitalsF block – filling 4f and 5f orbitals

Trends in the Periodic Table

• Atomic radius

• Increases with

increasing number

of energy levels

Atomic Size

Ionization

• Energy ejects an

electron from atom’s

orbit

• Forms a CationX -> X+

Shielding Effect

Trends in Ionization Energy

Low Energy = Easier to remove electron

High Energy = Difficult to remove electron

Periodic Size Changes

Electronegativity

Electronegativity Trend

Electronegativity

• Ability to attractAn electron

Forms a AnionX -> X-

Ion Sizes

Ion Sizes

Periodic Trends

Boiling Point

Boiling Point Trends

Elemental Abundance

1. Hydrogen

2. Helium

3. Oxygen

4. Carbon

Rare earth elements

Alchemy

Nuclear Fusion

4 1H -----------> 4He

occurs in the core of stars

Fusion in SuperGiant Stars

• Betelgeuse is a red giant star in Orion

that is currently fusing Helium

and will become a supernova

3 4He ---------> 12C

Synthetic Elements

Lawrence’s Cyclotron

Superheavy Elements

• Transuranium Elements

– Produced by nuclear collisions

Island of Stability