CHEMISTRY BOOTCAMP #1
MATTER* is anything that has mass and takes up space
Two things to consider when looking at different types of MATTER
TWO Types of MATTER
• PURE SUBSTANCE – Type of matter with a uniform and fixed composition
• MIXTURE – Two or more pure substances that have been physically combined and have a variable composition
TWO Types of PURE SUBSTANCES
• ELEMENT – pure substance that cannot be decomposed (broken down) by a chemical change
• COMPOUND – 2 or more elements that are chemically combined in a fixed proportion AND can be decomposed by a chemical change
Two Types of MIXTURES
• Homogeneous mixture – all parts are evenly distributed and look the same throughout
– Aqueous (aq) – mixed with water & is homogeneous
• Heterogeneous mixture – parts are not evenly distributed and look different throughout
Two Types of Matter
SEPARATING MIXTURES • Homogeneous mixtures require EVAPORATION
(CRYSTALLIZATION) because the solids are fully dissolved in the liquid – Ex: SALT WATER
– Salt is fully dissolved and mixture looks same throughout
• Heterogeneous mixtures require FILTRATION because the solids are large enough to be caught in a filter – Ex: SAND AND WATER
– You can see the sand and it does not dissolve in water
States of Matter
Yes No No
Yes Yes No
(s)
Ex: NaCl(s), CCl4(s)
(l)
Ex: H2O(l), Hg(l) (g)
Ex: O2(g), CO2(g)
Standard Temperature and Pressure (STP)
STP = Standard Temperature and Pressure Find on Table A. Standard Temperature: ____101.3 kPa____ Standard Pressure: ______273 K________
A substance has a melting point of 230 K and a boiling point of 769 K. What state of matter is this substance in at:
a) 300 K b) 100 K c) 1000 K d) 500 K e) STP
Property: a characteristic of a substance that can be observed
Physical Properties
Physical property: a property that can be observed without changing the identity of the substance
Examples:
• color
• odor
• luster
• malleability: the ability to be hammered into a thin sheet
• ductility: the ability to be stretched into a wire
• melting point
• boiling point
• conductivity
• solubility
• density
Chemical Properties
• Chemical property: a property that can only be observed by changing the identity of the substance
Examples:
•flammability
•ability to rust
•reactivity with vinegar
How do you know if it is chemical or physical? - If it CHanges, it’s CHemical
DENSITY is an important physical property. • Density - The amount of
“stuff” or particles (mass) in a given volume of space.
• Density is the mass of an object measured in grams, divided by the volume of an object measured in mL or cm3. The standard unit for density is g/cm3.
Example Problem: If an object has a mass of 3.0 grams and has a volume of 2 mL (2 cm3), what is the density of the object? Density= = = 1.5 g/mL or 1.5 g/cm3
Remember our density lab?
Physical Changes
• Changes that do NOT change the identity of the substance.
• You may or may not be able to undo a physical change.
Chemical Changes • Changes that do change the identity of a substance
• In other words, a chemical change is when something
changes into an entirely different substance
• For example: – Iron rusting – Wood burning – Copper turning to brass – Baking a cake – spoiled milk
The periodic table is organized by properties
– Elements with similar properties occupy the same general area of the periodic table
Metals and Nonmetals
Li
3
He
2
C
6
N
7
O
8
F
9
Ne
10
Na
11
B
5
Be
4
H
1
Al
13
Si
14
P
15
S
16
Cl
17
Ar
18
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
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
Rf
104
Db
105
Sg
106
Bh
107
Hs
108
Mt
109
Mg
12
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
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
La
57
Ac
89
1
2
3
4
5
6
7
METALS
Nonmetals
Metalloids
Nonmetals Metalloids Metals
plum-pudding rutherford bohr wave-mechanical
History of the Atom
Rutherford’s Nuclear Model: • Atom is mostly empty space • Dense, positively-charged nucleus (protons + neutrons) • Negatively-charged electron cloud surrounding the nucleus
The Atom
Key Points: • Atomic number – identifies an element & is the number of protons • Charge of atom is neutral – # of protons equals # of electrons • Charge of nucleus is positive – protons + neutrons = positive
Isotope – an atom of an element with a different number of neutrons
• All isotopes have different
masses • To get the mass of an isotope,
you add the # of protons and the # of neutrons
• Mass number - identifies an isotope - # of protons + # of neutrons
Calculating Average Atomic Mass • Boron exists as two isotopes: Boron-10 and Boron-11
• Boron-10 has a mass of 10.01 amu and makes up 19.9% of all boron that exists
• Boron-11 has a mass of 11.01 amu and makes up 80.1% of all boron that exists
• To calculate the average atomic mass of boron, multiply the mass of each boron isotope by its percent abundance