Exam Flashcards
(109 cards)
1
Q
Base unit
A
Defined unit in a system of measurement that is based on an object or event in the physical world
2
Q
Second (SI Unit)
A
The physical standard used to define the second is the frequency of the radiation given off by a cesium-133 atom. Time=second(s)
3
Q
Meter (SI Unit)
A
Length=meter (m) The distance that light travels in a vacuum in 1/299,792,458 of a second. A vacuum exists where space contains no matter
4
Q
Kilogram (SI Unit)
A
Mass=kilogram (kg) mass is the amount of matter an object contains
5
Q
Kelvin (SI Unit)
A
Temperature=kelvin (K) Zero kelvin is where all particles are at their lowest possible energy state. Water freezes at 273.15 K and boils at 373.15 K. K=Celsius+273
6
Q
Derived unit
A
A unit that is defined by a combination of base units
7
Q
Volume
A
The space occupied by an object (cm^3)
8
Q
Liter
A
Commonly used to measure the volume of water and beverage containers.
9
Q
Dimensional analysis
A
A systematic approach to problem solving that uses conversion factors to move, or convert, from one unit to another
10
Q
Conversion factor
A
A ratio of equivalent values having different units
11
Q
Accuracy
A
Refers to how close a measured value is to an accepted value.
12
Q
Precision
A
Refers to how close a series of measurements are to one another
13
Q
Error
A
Defined as the difference between an experimental value and accepted value
14
Q
Percent error
A
Expresses error as a percentage of the accepted value
Percent error=(error/accepted value)x100
15
Q
Density
A
Physical property of matter and is defined as the amount of mass per unit volume.
Density=mass/volume
16
Q
Graph
A
Visual display of data
17
Q
Circle graph
A
Useful for showing parts of a fixed whole
18
Q
Bar graphs
A
Used to show hoe a quantity varies across categories. The quantity being measured appears on the vertical axis (y-axis). The independent variable appears on the horizontal axis (x-axis).
19
Q
Line graphs
A
Most common in chemistry. The points represent the intersection of data for two variables. The independent variable is plotted on the x-axis. The dependent variable is plotted on the y-axis
20
Q
Slope
A
Slope=rise/run when the mass of a material is plotted against its volume, the slope of the line represents the material’s density.
21
Q
Significant figure—adding and subtracting
A
The answer must be rounded to the least precise place
22
Q
Significant figure—multiplication and division
A
Answer must be rounded to the least number of significant figures in the numbers multiplied or divided
23
Q
States of matter
A
Physical forms of all matter that exists naturally on Earth
24
Q
Solid
A
Form of matter that has its own definite shape and volume
25
Liquid
A form of matter that flows, has constant volume, and takes the shape of its container
26
Gas
Form of matter that not only flows to conform to the shape of its container but also fills the entire volume of its container
27
Physical property
Characteristic of matter that can be observed or measured without changing the sample's composition.
Examples: density, color, odor, hardness, melting point, boiling point
28
Extensive properties
Physical properties that are dependent on the amount of substance present.
Examples: mass, length, volume
29
Intensive properties
Physical properties that are independent of the amount of substance present.
Example: density is the same no matter how much substance is present
30
Chemical property
The ability or inability of a substance to combine with or change into one or more other substances
Example: rusting
31
Physical change
A change that alters a substance without changing its composition
32
Phase change
Transition of matter from one state to another
33
Chemical change
A process that involves one or more substances changing into new substances, commonly referred to as a chemical reaction
34
Law of conservation of mass
States that mass is neither created created nor destroyed during chemical reaction—it os conserved
Mass(reactants)=mass(products)
35
Mixture
A combination of two or more pure substances in which each pure substance retains its individual chemical properties.
36
Heterogeneous mixture
A mixture that does not blend smoothly throughout and in which the individual substances remain distinct
37
Homogeneous mixture
Mixture that has constant composition throughout; it always has a single phase
38
Solutions
A uniform mixture that can contain solids, liquids, or gases; also called a homogeneous mixture
39
Element
A pure substance that cannot be separated into simpler substances by physical or chemical means
40
Periodic table
Organizes the elements into a grid of horizontal rows called periods and vertical columns called groups or families
41
Compound
Pure substances made up of two or more different elements that are combined combined chemically
42
Democritus
- matter is composed of atoms, which move through empty space.
- atoms are solid, homogeneous, indestructible, and indivisible.
- different kinds of atoms have different sizes and shapes.
- size, shape, and movement of atoms determine the properties of matter
43
Aristotle
- empty space cannot exist
| - matter is made of earth, fire, air, and water
44
Dalton
- matter is composed of extremely small particles called atoms
- atoms are indivisible and indestructible
- atoms of a given element are identical in size, mass, and chemical properties
- atoms of a specific element are different from those of another element
- different atoms combine in simple whole-number ratios to form compounds
- in a chemical reaction, atoms are separated, combined or rearranged
45
Law of Definite proportions
States that, regardless of the amount, a compound is always composed of the same elements in the same proportion by mass
46
Law of Multiple Proportions
States that when different compounds are formed by the combination of the same elements, different masses of one element combine with the same fixed mass of the other element in a ratio of small whole numbers
47
Atomic structure
At the centre of an atom is a nucleus containing protons and neutrons. Electrons are arranged around the nucleus in energy levels or shells
48
Isotopes
Atoms with the same number of protons but different numbers of neutrons
49
Mass number
The sum of the atomic number (or number of protons) and neutrons in the nucleus
50
Isotope symbol
(mass number/atomic number)Chemical Symbol
51
Atomic mass unit (amu)
One-twelfth the mass of a carbon-12 atom
52
Radioactivity
The process in which some substances spontaneously emit radiation
53
Radiation
The rays and particles emitted by the radioactive materials
54
Nuclear reaction
A reaction that involves a change in an atom's nucleus
55
Radioactive decay
Unstable nuclei lose energy by emitting radiation in this spontaneous process
56
Alpha radiation
The radiation that was deflected toward the negatively charged plate
57
Alpha particle
Contains two protons and two neutrons, and thus has a 2+ charge, which explains why alpha particles are attracted to the negatively charged plate
58
Nuclear equation
Equation that shows the atomic numbers and mass numbers of the particles involved
59
Beta radiation
The radiation that was deflected toward the positively charged plate
60
Beta particle
And electron with a 1- charge
61
Gamma ray
A high-energy radiation that possesses no mass and is denoted by the symbol
62
Beta decay
A radioisotope that lies above the band of stability is unstable because it has too many neutrons relative to its number of protons.
63
Alpha decay
All nuclei with more than 82 protons are radioactive and decay spontaneously
64
Electromagnetic radiation
A form of energy that exhibits wavelike behavior as it travels through space
65
Nuclear power plant
In the chamber there are are control rods that control fission and absorb neutrons, and fuel rods with uranium in them. When the control rods are taken out, fission occurs which heats the water. The steam rises which heats a turbine that creates electricity through the generator. When the steam in the turbine cools it goes back to the chamber to be reheated
66
Wavelength
The shortest distance between equivalent points on a continuous wave
67
Frequency
The number of waves that pass a given point per second (Hz)
68
Amplitude
The wave's height from the origin to a crest, or from the origin to a trough
69
Electromagnetic Wave Relationship
Speed of light in a vacuum (c)= (wavelength)(frequency)
70
Relationship between wavelength and frequency
As wavelength increases, frequency decreases
71
What happens when light passes through a prism?
It is separated into a continuous spectrum of its different components—red, orange, yellow, green, blue, indigo, and violet light
72
Electromagnetic spectrum
Includes all forms of electromagnetic radiation; the types of radiation differ in their frequencies and wavelengths
73
Bohr's Model of the Atom
Depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus
74
Ground state
The lowest allowable energy state of an atom
75
Quantum number
The number assigned to each orbit of an electron
76
Quantum
The minimum amount of energy that can be gained or lost by an atom
77
Quantum mechanical model of the atom
An atomic model in which electrons are treated as waves; also called the wave mechanical model of the atom
78
De Broglie Equation
Predicts that all moving particles have wave characteristics
79
Particle Electromagnetic-Wave Relationship
Wavelength=Planck's constant/(mass of the particle)(velocity)
80
Heisenberg uncertainty principle
States that it is fundamentally impossible to know precisely both the velocity and position of a particle at the same time.
81
Atomic orbital
Three-dimensional region around the nucleus which describes the electron's probable location
82
Energy sub levels
The energy levels contained within a principal energy level
83
Shapes of orbitals
- Sublevels are labeled s, p, d, or f according to the shapes of the atom's orbitals
- each orbital can contain, at most, two electrons
84
Electron configuration
The arrangement of electrons in an atom
85
Aufbau principle
States that each electron occupies the lowest energy orbital available
86
Pauli exclusion principle
States that a maximum of two electrons can occupy a single atomic orbital, but only if the electrons have opposite spins
87
Hund's rule
States that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals
88
Noble-gas notation
The electron configuration for an element can be represented using the noble-gas notation for the noble gas in the previous period and the electron configuration for the additional orbitals being filled
89
Valence electrons
Electrons in the atom's outermost orbitals—generally those orbitals associated with the atom's highest principal energy level
90
Periodic law
The statement that there is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number
91
John Newlands
- arranged elements by increasing atomic mass
- noticed the repetition of properties every eighth element
- created the law of octaves
92
Lothar Meyer
- demonstrated a connection between atomic mass and elements' properties
- arranged the elements in order of increasing atomic mass
93
Dmitri Mendeleev
- demonstrated a connection between atomic mass and elements' properties
- arranged the elements in order of increasing atomic mass
- predicted the existence and properties of undiscovered elements
94
Henry Moseley
- discovered the atom contain a unique number of protons called the atomic number
- arranged elements in order of increasing atomic number, which resulted in a periodic pattern of properties
95
Groups
A vertical column of elements in the periodic table arranged in order of increasing atomic number; also called a family
96
Periods
A horizontal row of elements in the modern periodic table
97
Excited state
When an atom gains energy
98
Atomic radius
The measure of the size of atoms. The distance from the atomic nucleus to the outermost electron orbital
99
Ionization energy
The energy required to remove an electron from a gaseous atom
100
Periodic trends
Atomic radius: decreases across and increases down
| Ionization energy: increases across and decreases down
101
Metals
Elements that are generally shiny when smooth and clean, solid at room temperature, and good conductors of heat and electricity
102
Nonmetals
Elements that are generally gases or brittle, dull-looking solids
103
Metalloids
Have physical and chemical properties of both metals and nonmetals
104
Ion
An atom or a bonded group of atoms that has a positive or negative charge
105
Chemical bond
The force that holds two atoms together
106
Cation
Positively charged ions that forms when an atom loses one or more valence electrons in order to attain a noble gas configuration
107
Anion
A negatively charged ion
108
Inverse proportion
When one value increases the other value decreases
109
Direct proportion
When one value increases the other value increases by the same percentage
