1. Periodic Table

2. The first periodic table?

3. Discovering the Periodic TableNe Ar Kr Xe Po Rn Ra Eu Lu Pa Ac C S Fe Cu Ag Sn Au Hg Pb
Ancient Times Tc Hf Re At Fr Pm Np Pu Am Cm Bk Cf Es Fm Md No Lr He Sc Ga Ge Rb Ru In Cs Tl Pr Nd Sm Gd Dy Ho Tm Yb La Cr Mn Li K N O F Na B Be H Al Si Cl Ca Ti V Co Ni Se Br Sr Y Zr Nb Mo Rh Pd Cd Te I Ba Ta W Os Ir Mg Ce Tb Er Th U P Zn As Sb Pt Bi
Midd Rf Db Sg Bh Hs Mt
1965-
The Noble Gases
At the start of the 1890s, no one had any idea that there was a separate group of gases in the periodic table, the noble gases. Noble gases are familiar to us from their use in neon signs and helium balloons. By 1900 this whole new group had been identified and isolated. While trying to determine an accurate atomic mass for nitrogen, British physicist Lord Raleigh ( ) discovered that nitrogen prepared from ammonia was noticeably lighter than nitrogen that came from the atmosphere. He and William Ramsay ( ) both studied “atmospheric” nitrogen. By removing the nitrogen from it, they produced a tiny quantity of another gas. Since it did not react with anything they called it argon, from the Greek word for lazy. The discovery of helium followed a year later in Ramsay and his assistant Morris Travers ( ) then started to search for additional elements in this new group. They attempted this by fractional distillation of large quantities of liquid air and argon. In 1898, their efforts were rewarded; they had prepared krypton, neon, and xenon.
Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 32
Journal of Chemical Education, Sept. 1989

4. Melting Points H He Mg Symbol Melting point oC Li Be B C N O F Ne
-259.2 He
-269.7 1 1 Mg
650
Symbol
Melting point oC Li
180.5 Be
1283 B
2027 C
4100 N
-210.1 O
-218.8 F
-219.6 Ne
-248.6 2 2
> 3000 oC oC Na 98 Mg
650 Al
660 Si
1423 P
44.2 S
119 Cl
-101 Ar
-189.6 3 3 K
63.2 Ca
850 Sc
1423 Ti
1677 V
1917 Cr
1900 Mn
1244 Fe
1539 Co
1495 Ni
1455 Cu
1083 Zn
420 Ga
29.78 Ge
960 As
817 Se
217.4 Br
-7.2 Kr
-157.2 4 4 Rb
38.8 Sr
770 Y
1500 Zr
1852 Nb
2487 Mo
2610 Tc
2127 Ru
2427 Rh
1966 Pd
1550 Ag
961 Cd
321 In
156.2 Sn
231.9 Sb
630.5 Te
450 I
113.6 Xe
-111.9 5 5 Cs
28.6 Ba
710 La
920 Hf
2222 Ta
2997 W
3380 Re
3180 Os
2727 Ir
2454 Pt
1769 Au
1063 Hg
-38.9 Tl
303.6 Pb
327.4 Bi
271.3 Po
254 At Rn
-71 6 6
Ralph A. Burns, Fundamentals of Chemistry , 1999, page 1999

5. Densities of Elements H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K
0.071 He
0.126 1 1 Li
0.53 Be
1.8 B
2.5 C
2.26 N
0.81 O
1.14 F
1.11 Ne
1.204 2 2 Na
0.97 Mg
1.74 Al
2.70 Si
2.4 P
1.82w S
2.07 Cl
1.557 Ar
1.402 3 3 K
0.86 Ca
1.55 Sc
(2.5) Ti
4.5 V
5.96 Cr
7.1 Mn
7.4 Fe
7.86 Co
8.9 Ni
8.90 Cu
8.92 Zn
7.14 Ga
5.91 Ge
5.36 As
5,7 Se
4.7 Br
3.119 Kr
2.6 4 4 Rb
1.53 Sr
2.6 Y
5.51 Zr
6.4 Nb
8.4 Mo
10.2 Tc
11.5 Ru
12.5 Rh
12.5 Pd
12.0 Ag
10.5 Cd
8.6 In
7.3 Sn
7.3 Sb
6.7 Te
6.1 I
4.93 Xe
3.06 5 5 Cs
1.90 Ba
3.5 La
6.7 Hf
13.1 Ta
16.6 W
19.3 Re
21.4 Os
22.48 Ir
22.4 Pt
21.45 Au
19.3 Hg
13.55 Tl
11.85 Pb
11.34 Bi
9.8 Po
9.4 At
--- Rn
4.4 6 6
Element Year Discovered Density (g/cm3)
Osmium
Iridium
Platinum
Rhenium
Neptunium
Plutonium
Gold prehistoric
Tungsten
Uranium
Tantalum
8.0 – 11.9 g/cm3
12.0 – 17.9 g/cm3
> 18.0 g/cm3 Mg
1.74
Symbol
Density in g/cm3C, for gases, in g/L W

6. Oxidation State of Elements
Group 1 18
Be2+
Na+ K+
Rb+
Cs+
Ba2+ H+
Li+
Ca2+
Sr2+
Mg2+ N
O B L E G A S 1 1 2 13 14 15 16 17
N3-
O2-
F1- 2 2
Al3+
S2-
Cl1- 3 3
Transition metals
Period
Zn2+
Se2-
Br1- 4 4
Ag1+
Te2-
I1- 5 5 6 6

7. Mendeleev late 1800’s
Grouped elements with similar properties into columns.
Russian, late 1800’s. noble gases discovered after him (1890’s).
Chemical properties- how they react with other substances
Physical properties- density, color, melting/boiling point, mass

8. Mendeleev’s Periodic Law
The properties of the elements are a periodic function of their atomic masses.
Atomic number wasn’t known at the time.

9. Today’s Periodic Law
The properties of the elements are a periodic function of their atomic numbers.
Using x-rays, Moseley determined the number of protons per element (atomic number).

10. The Periodic Table * Y * Lanthanides Y Actinides Alkaline H He Li Be B
Noble
gases
Alkaline
earth metals
Halogens 1 18 H 1 He 2 2 13 14 15 16 17 Li 3 Be 4 B 5 C 6 N 7 O 8 F 9 Ne 10 Na 11 Mg 12 3 4 5 6 7 8 9 10 11 12 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18
Transition metals K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36
Alkali metals Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 Cs 55 Ba 56 * Hf 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 Fr 87 Ra 88 Y Rf
104 Db
105 Sg
106 Bh
107 Hs
108 Mt
109
Uun
110
Uuu
111
Uub
112
Uuq
113
Uuh
116
Uuo
118
* Lanthanides La 57 Ce 58 Pr 59 Nd 60 Pm 61 Sm 62 Eu 63 Gd 64 Tb 65 Dy 66 Ho 67 Er 68 Tm 69 Yb 70 Lu 71
Y Actinides Ac 89 Th 90 Pa 91 U 92 Np 93 Pu 94 Am 95 Cm 96 Bk 97 Cf 98 Es 99 Fm
100 Md
101 No
102 Lr
103

11. Representative elements
Filling the s and p sublevels

12. METALS Metals and Nonmetals Nonmetals Metalloids H He Li Be B C N O F1 He 2 1 Li 3 Be 4 B 5 C 6
Nonmetals N 7 O 8 F 9 Ne 10 2 Na 11 Mg 12 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18 3 K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36 4
METALS Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 5
Metalloids Cs 55 Ba 56 Hf 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 6 * Fr 87 Ra 88 Rf
104 Db
105 Sg
106 Bh
107 Hs
108 Mt
109 7 W La 57 Ce 58 Pr 59 Nd 60 Pm 61 Sm 62 Eu 63 Gd 64 Tb 65 Dy 66 Ho 67 Er 68 Tm 69 Yb 70 Lu 71 Ac 89 Th 90 Pa 91 U 92 Np 93 Pu 94 Am 95 Cm 96 Bk 97 Cf 98 Es 99 Fm
100 Md
101 No
102 Lr
103

13. Metals Luster (shine) Ductile (can be pulled into wires) Malleable
Good conductors of heat and electricity
Have ≤3 valence electrons so tend to lose electrons
copper
Most elements. Only one is a liquid at room temperature. Why is hydrogen in column 1 if it is not a metal?
strontium
manganese

14. Nonmetals Brittle or gaseous Insulators
Have 5 or more valence electrons, so tend to gain (or share) electrons
phosphorus
sulfur

15. Metalloids Elements with properties of both metals and nonmetals
Located on a diagonal between metals and nonmetals.
germanium
arsenic
silicon

17. Octet Rule
Eight electrons in the outer energy level make an atom unreactive or stable.
Why would that rule still apply to elements in the 4th period, where the d sublevel is filling?

18. Reactivity
The most active metals are in the lower left corner, and the most active nonmetals are in the upper right corner.

19. Atomic radii
Noble gases have been found to be larger than the element immediately to their left on the PT. They are not interacting with other atoms of the same element, like most crystals do.

20. Atomic Radii
Increases down a group, since they have increasing energy levels.
Decreases across a period due to increasing nuclear charge (the force of attraction between nucleus and electrons).

21. Ions
Metals lose an electron, giving them a positive charge, and decreasing their radius.
Nonmetals gain electrons, giving them a negative charge, and increasing their radius.
Anion, cation

22. Top row- atomic radii
Bottom row- ionic radii
Na+ ion loses its 3s e-, decreasing by one energy level & the same no. of protons are attracting fewer electrons.
Cl- ion gains an e-, giving it an -1 charge.
Metallic ions (lt) are formed by losing e- so their ionic radii are smaller than their atomic radii.
Nonmetals gain e- so their ions are larger than their atoms.

23. Ionization energies
Energy needed to remove an electron from an atom (kJ/mol)
Going across a period it increases due to increasing nuclear charge.
Going down a group, the ionization energy decreases due to increased atomic radius and the shielding effect.
Second ionization energy- the energy required to remove a second electron from an atom.
These ionization energy patterns are evidence of energy levels.

24. Electrons from a full or half-full sublevel require more energy to remove.

25. Ionization Energies (kJ/mol)
Element Na Mg Al Si P S Cl Ar
1st
498
736
577
787
1063
1000
1255
1519
2nd
4560
1445
1815
1575
1890
2260
2295
2665
3rd
6910
7730
2740
3220
2905
3375
3850
3945
4th
9540
10,600
11,600
4350
4950
4565
5160
5770
5th
13,400
13,600
15,000
16,100
6270
6950
6560
7320
6th
16,600
18,000
18,310
19,800
21,200
8490
9360
8780
Ionization energy increases with the removal of each additional electron.
Metals have low ionization energy; nonmetals have high ionization energy.
This experimental data gives evidence for:
1) effect of increasing nuclear charge
2) stability of octet
3) effect of increased radius
4) s & p sublevel in outer level
SUGGESTION: Emphasize that theories came from experimental evidence!
Herron, Frank, Sarquis, Sarquis, Cchrader, Kulka, Chemistry 1996, Heath, page
Shaded area on table denotes core electrons.

26. Electronegativity
The power of an atom in a molecule to attract electrons to itself.
Decrease from top to bottom
Increase from left to right
F has the highest
Elements with high electron affinities gain electrons, forming negative ions.
The more stable an atom is, the less likely it will attract an e- (giving it a negative electron affinity).

27. Electronegativities Period H B P As Se Ru Rh Pd Te Os Ir Pt Au Po At
2.1 B
2.0 P As Se
2.4 Ru
2.2 Rh Pd Te Os Ir Pt Au Po At 1 1 2A 3A 4A 5A 6A 7A
Actinides: Li
1.0 Ca Sc
1.3 Sr Y
1.2 Zr
1.4 Hf Mg La
1.1 Ac
Lanthanides: * y Be
1.5 Al Si
1.8 Ti V
1.6 Cr Mn Fe Co Ni Cu
1.9 Zn
1.7 Ga Ge Nb Mo Tc Ag Cd In Sn Sb Ta W Re Hg Tl Pb Bi N
3.0 O
3.5 F
4.0 Cl C
2.5 S Br
2.8 I 2 2 Na
0.9 K
0.8 Rb Cs
0.7 Ba Fr Ra
Below 1.0 3 3 3B 4B 5B 6B 7B 8B 1B 2B
Period 4 4 5 5 6 6
Linus Pauling ( ) awarded Nobel Prize in chemistry in 1954 for his 1939 text, The Nature of the Chemical Bond,
and also won the Nobel Peace Prize in 1962 for his fight to control nuclear weapons.
The greater the electronegativity of an atom in a molecule, the more strongly it attracts the electrons in a covalent bond. 7
Hill, Petrucci, General Chemistry An Integrated Approach 2nd Edition, page 373