Exam 1 chem 1200 Flashcards
1
Q
Who Proposed that at the same temperature and pressure, equal volumes of different gases contain the same number of particles?
A
Amadeo Avogadro
2
Q
Particles found in the nucleus of an atom
A
Protons
3
Q
A set of hypothesis that attempts to explain a natural phenomenon
A
Theory
4
Q
The fundamental SI unit for length
A
Meters
5
Q
nano——n
A
10^-9
6
Q
micro
A
10^-6
7
Q
milli——m
A
10^-3
8
Q
centi—-c
A
10^-2
9
Q
deci—–d
A
10^-1
10
Q
deca—-da
A
10^1
11
Q
hecto—h
A
10^2
12
Q
kilo—–k
A
10^3
13
Q
mega—M
A
10^6
14
Q
SI Fundamental unit for time?
A
second
15
Q
SI Fundamental unit for mass?
A
kilogram
16
Q
SI Fundamental unit for Temp?
A
kelvin
17
Q
SI Fundamental unit for Electrical current?
A
ampere
18
Q
SI Fundamental unit for amount?
A
mole
19
Q
1 decameter^3 is = to ?L
A
1
20
Q
1 ml is = to how many cc?
A
1
21
Q
Definition:
Agreement of a particular value with the true value
A
Accuracy
22
Q
Definition:
Degree of agreement among several measurements of the same quantity.
A
Precision
23
Q
Nonzero integers always count as significant figures
how many sig figs in 4563?
A
4
24
Q
Leading zeros are zeros that precede all the nonzero digits. These do not count as significant figures
how many sig figs in 0.031?
A
2
25
Captive zeros are zeros between nonzero digits. These always count as significant figures
How many sig figs in 41.04?
4
26
Trailing zeros are zeros at the right end of the number. They are significant only if the number contains a decimal loin
How many sig figs are in examples 1 and 2?
1--- 2.400
2--700
1- 4 sig figs
| 2-1 sig fig
27
1 inch is equal to how many cm?
2.54cm
28
How do you calculate sig figs in multiplication/division?
For multiplication or division, the number of significant figures in the result is the same as the number in the least precise measurement used in the calculation
29
how do you calculate sig figs in +/-?
For addition or subtraction, the result has the same number of decimal places as the least precise measurement used in the calculation
30
what has visibly indistinguishable parts; solution.
homogenous mixture
31
what has visibly distinguishable parts?
heterogenous mixture
32
Change in the form of a substance, not in its chemical composition...Can be used to separate a mixture into pure compounds, but it will not break compounds into elements
Physical Change
| Example: boiling or freezing water
33
A given substance becomes a new substance or substances with different properties and different composition
Chemical Change
| Example: Bunson Burner
34
Who: Element: A substance that cannot be broken down into simpler substances. AKA the father of Modern Chem
Robert Boyle
35
Definition: Atom
* Matter is composed of tiny particles called atoms.
| * Atom:smallest part of an element that is still that element.
36
Definition: One substance changes to another by reorganizing the way the atoms are attached to each other
A Chemical Reaction
37
what is Process that lies at the center of scientific inquiry?
The Scientific Method
38
Which law states Mass is neither created nor destroyed in a chemical reaction
Law of conservation of mass (Lavoisier)
39
Which law states A given compound always contains exactly the same proportion of elements by mass
Law of definite proportion (Proust)
40
What is the Law of multiple proportions?
When two elements form a series of compounds, the ratios of the masses of the second element that combine with 1 gram of the first element can always be reduced to small whole numbers
41
Who: Each element is made up of tiny particles called atoms
The atoms of a given element are identical;
the atoms of different elements are different in some fundamental way or ways
Dalton
42
Who: Chemical compounds are formed when atoms of different elements combine with each other. A given compound always has the same relative numbers and types of atoms
-Chemical reactions involve reorganization of the atoms—changes in the way they are bound together. The atoms themselves are not changed in a chemical reaction.
Dalton
43
Who: Measured (under same conditions of T and P) the volumes of gases that reacted with each other.
Gay—Lussac
44
Who: At the same T and P, equal volumes of different gases contain the same number of particles.
Avogadro
45
Who: Postulated the existence of electrons using cathode-ray tubes.
Determined the charge-to-mass ratio of an electron.
The atom must also contain positive particles that balance exactly the negative charge carried by particles that we now call electrons.
Pllum pudding model
JJ Thomas
46
Who: Performed experiments involving charged oil drops.
Determined the magnitude of the charge on a single electron.
Calculated the mass of the electron. 9.11 x 10-31 kilograms
Robert Millikan
47
Who: Explained the nuclear atom.
Atom has a dense center of positive charge
called the nucleus.
Electrons travel around the nucleus at a relatively large distance
Ernest Rutherford (1911)
48
Definition: Isotopes
Atoms with the same number of protons but different numbers of neutrons.
Show almost identical chemical properties; chemistry of atom is due to its electrons.
In nature most elements contain mixtures of isotopes.
49
A certain isotope X contains 23 protons and 28 neutrons.
| • What is the mass number of this isotope? • Identify the element.
Mass Number = 51 Vanadium
50
What is a Mole?
Mole – a unit for counting atoms and molecules
| 1 mole = 6.022×1023
