Transcript Elements

Matter
Matter
1. Where do atoms come from?
2. Are new atoms being made right now on the
earth?
3. If so, how? Where?
4. Are new atoms being made anywhere right now?
5. If so, how? Where?
Matter
Elements
1. Elements - contain only one type of atom
2. 90 naturally occuring elements (Uranium, 92
heaviest naturally occuring)
3. Transuranium (synthetic) elements
4. Types of elements
a) Monoatomic – Fe, Au
b) Molecular – H2, N2, O2, P4, C60
Matter
Matter
Origin of the Elements
Matter
Origin of the Elements
Matter
Supernova
Remnant
Matter
Origin of the Elements
Abundance (by mass)
Earth’s Crust: 46% O
Body:
65 % O
Universe: 90% H and 10% He
Matter
History: The Atom
Democritus
1. Atomos – Indivisible (~400 B.C.)
2. Smallest particle of a substance that retains the
properties of that substance
3. Only “Atoms and the Void”
Matter
Matter
History: The Atom
John Dalton’s Atomic Theory (1803)
a. All matter is made of indivisible
particles called atoms
b. Atoms of same element have same
properties
c. Atoms combine in small, whole #
ratios
d. Chemical reactions are merely the
rearrangement of atoms
Matter
Symbols for Elements
Jons Berzelius –
standardized names
and symbols of the
elements
Strontium = Sr
Matter
Matter
Names for Elements
a. Greek & Latin
Na = Natrium
K = Kalium
Li = Lithos
b. Places (Ge, Fr, Cf)
Y, Yb, Er, Tb = Ytterby
c. Scientists (Es, Fm, Cm)
Matter
History: The Electron
J.J. Thomson (1897) – discovered the electron
with a Cathode Ray Tube
Matter
History: The Electron
Matter
History: The Electron
Matter
History: The Electron
Matter
History: The Electron
Matter
Matter
History: The Electron
Thomson Plum Pudding Model
Matter
History: The Nucleus
Rutherford (1911)
1. Discovered Nucleus
2. Gold Foil
Experiment
Matter
History: The Nucleus
1:8000 bounced back (10,000 miles/s)
Matter
Matter
History: The Nucleus
Matter
History: The Nucleus
3. Results
a. Nucleus is heavy and dense
b. 99.9% of atom’s mass is in the nucleus
c. Electrons “orbit” the nucleus
d. Most of the atom is empty space
Matter
Matter
History: The Proton
Rutherford (1914)
1. Had been suspected to exist since 1886
(Goldstein’s canal rays)
2. 1836 times heavier than the electron
Matter
History: The Neutron
1. Discovered last (1932) by Chadwick
2. Roughly same mass as proton
Matter
The
World’s
Most
Famous
Neutron
Matter
Particle
Charge
Mass
Proton
+1
~1 g/mol
Electron
-1
0.00055
g/mol
(1/1836)
Neutron
0
~1 g/mol
Matter
Matter
Scanning Tunneling Microscope
History: The Atom
Matter
History: The Atom
Matter
Protons, Neutrons and Electrons
Reading the boxes
3
9
Li
6.941
F
18.994
Matter
Isotopes
1. Isotopes – Atoms with the same # of protons, but
different # of neutrons
2. Elements often exist as a mixture of isotopes
Protons
Copper-63
Copper-65
Neutrons
Electrons
p
n
E
Isotopes
92Zr
38
50
38
11
13
11
55
79
55
233Th
Matter
Isotopes
•
Cancer treatment (60Co gives off gamma
rays)
• Medical Tracers (24Na for circulatory
system)
• 14C dating
a. Mummies
b. Shroud of Turin
4. Nuclear fuel (235U and 239Pu)
Matter
Isotopes
1. Some isotopes are more common
2. Hydrogen example
1H
2H (deuterium)
3H (tritium)
3. Atomic Mass – Weighted Average of the
isotopes
Matter
Matter
Average Atomic Mass
4. What is the ave atomic mass of Gallium if
it exists as 60.30% 69Ga (68.926 g/mol)
and 39.70% 71Ga (70.926 g/mol)?
(Ans: 69.72 g/mol)
Matter
Average Atomic Mass
5. Out of 400 chlorine atoms, 302 are 35Cl
(34.969 g/mol), and 98 are 37Cl (36.966
g/mol). Average atomic mass?
6. What is average atomic mass of Copper if
69.09% exists as 63Cu (62.9298 g/mol) and the
rest exists as 65Cu (64.9278 g/mol)?
(0.6909)(62.9298) = 43.48
(
)(64.9278) = 20.07
63.55 g/mol
Matter
Ions
•
•
Cation – positive ion (more p than e)
Anion – Negative ion (more e than p)
p
n
e
9
26
17
10
30
18
10
23
18
16O223Na+
p
n
e
Ions
13C
90Sr
16
16
14
16
18
18
35
44
36
19
21
18
24Mg2+
15N3-
Matter
Group the following
Au
C
Be
C60
Te
H2O
P4
N2
NH3
S8
O2
P2O5
C2H4
Cl2
C6H12O6
Matter
Compounds
1. Compounds - Composed of two or more
different elements
2. Examples
H2O, CH4, NaCl, Fe2(SO4)3
3. Are there more elements or compounds?
Elements –
Compounds -
Matter
What is a Molecule?
1. Group of atoms held together by covalent
and polar covalent bonds (SHARING)
2. Usually composed of non-metals
3. Separate (discrete) groups of atoms
4. Molecular Elements - H2, P4
Molecular Compounds - CH4, H2O2
Matter
Diatomic Molecular Elements
H2
N2
O2
F2
Cl2
Br2
I2
Hydrogen
Nitrogen
Oxygen
Fluorine
Chlorine
Bromine
Iodine
Matter
Diatomic Elements
Matter
Matter
Diatomic Elements
Matter
What is an Ionic Compound?
1. Usually start with a metal
2. Composed of ions – No sharing but stealing
of ecation – positive ion
anion – negative ion
3. Example: NaCl, CaCl2, FeSO4
4. Formula Unit – instead of molecule
Matter
Matter
Ionic or molecular?
HCl
CO2
H2O
BaF2
VO3
Write the formula for the compound between:
Na+ and O2Al3+ and O2K+ and PO43Ba2+ and NO3-
BrK+
Ca2+
Al3+
NH4+
Cu2+
O2-
N3-
NO3-
SO42-
Matter
CO32-
Protons
C=
O=
NH4+
Electrons
Matter
The Key to the Universe
Quarks
Protons
Neutrons
Electrons
Elements
Compounds
Matter
10.
(d)
Matter
11.a) 193, 79 b) 132, 52
d) 39, 17
13.
protons neutrons
92
142
92
143
92
146
21.Palladium (Pd)
23. 1H is the most common
c) 118, 53
electrons
92
92
92
15
Matter
Isotope
Isotopic
Notation
Tungsten184
184
Sodium23
23
Astatine200
200
Promethi
um-148
Palladium
-109
Atomic #
Mass #
Protons
Neutrons
Electrons
74W
74
184
74
110
74
11Na
11
23
11
12
11
85
200
85
115
85
61
148
61
87
61
46
109
46
63
46
85At
148
61P
m
109 Pd
46
Vanadium
-48
48
23V
23
48
23
25
23
Scandium
-50
50
21Sc
21
50
21
29
21
Matter
Ion
Protons Neutrons Electrons
Ion
14N+
7
7
6
80Br-
15N2+
7
8
5
24Mg2+
14N-
7
7
8
27Al3+
81Br-
35
46
36
27Al2+
56Fe2+
26
30
24
19F-
31P3-
15
16
18
238U2+
119Sn4+
50
69
46
123I-
a)
24.28 g/mol
Matter
b) 12.01 g/mol
c) 63.55 g/mol
d) 6.925 g/mol
e) 20.192 g/mol
f) 28.09 g/mol
g) 178.55 g/mol
h) Boron-11
i) Bromine – 80
j) Chlorine - 35
28.
64.27 g/mol
Matter
58.a) 38, 36
b) 15, 18 c) 23, 20
d) 15, 14
e) 40, 42
60.a) Sn2+
b) Ic) AlO2- d) ClF3+
48
Ca(ClO4)2 Mg3(PO4)2
Matter
51 b) Ni(ClO4)2
53 a) Al2S3
Cr2(C2O4)3