PICLEC: MODULE 1 Flashcards
1
Q
The science that describes matterβits properties, the changes it undergoes, and the energy changes that accompany those processes
A
CHEMISTRY
2
Q
The CENTRAL SCIENCE
A
CHEMISTRY
3
Q
Branches of Chemistry
A
- ORGANIC CHEMISTRY
- INORGANIC CHEMISTRY
- ANALYTICAL CHEMISTRY
- BIOCHEMISTRY
- PHYSICAL CHEMISTRY
4
Q
BRANCH OF CHEMISTRY
- Hydrocarbons and its derivatives
A
ORGANIC CHEMISTRY
5
Q
BRANCH OF CHEMISTRY
- Inorganic compounds, metals, minerals
A
INORGANIC CHEMISTRY
6
Q
BRANCH OF CHEMISTRY
- Detection and identification of substances present (qualitative analysis) or amount of each substance (quantitative analysis)
A
ANALYTICAL CHEMISTRY
7
Q
BRANCH OF CHEMISTRY
- Processes in living organisms
A
BIOCHEMISTRY
8
Q
BRANCH OF CHEMISTRY
- Behavior of matter
A
PHYSICAL CHEMISTRY
9
Q
Anything that has mass and occupies space; is tangible
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MATTER
10
Q
Measure of the quantity of matter
A
MASS
11
Q
Amount of space
A
VOLUME
12
Q
The capacity to do work or to transfer heat
A
ENERGY
13
Q
TYPES OF ENERGY:
A
- KINETIC ENERGY
- POTENTIAL ENERGY
14
Q
TYPES OF ENERGY
- Energy in motion
A
KINETIC ENERGY
15
Q
TYPES OF ENERGY
- Energy at rest
A
POTENTIAL ENERGY
16
Q
ENERGY CHANGES:
A
- EXOTHERMIC
- ENDOTHERMIC
17
Q
ENERGY CHANGES
- Release (heat)
A
EXOTHERMIC
18
Q
ENERGY CHANGES
- Absorbs (heat)
A
ENDOTHERMIC
19
Q
STATES OF MATTER
A
- SOLID
- LIQUID
- GAS
20
Q
STATES OF MATTER
- Molecules packed close together orderly; Rigid
A
SOLID
21
Q
STATES OF MATTER
- Molecules are close but randomly arranged; Flows and assumes shape of container
A
LIQUID
22
Q
STATES OF MATTER
- Molecules are far apart; Fills any container
completely
A
GAS
23
Q
CHANGES OF STATES
A
S - L = MELTING
L - S = FREEZING
L - G = BOILING
G - L = CONDENSATION
G - S = DEPOSITION
S - G = SUBLIMATION
24
Q
Can be observed or measured without changing the identity of the substance.
e.g. color, hardness, melting point, boiling point
A
PHYSICAL PROPERTIES
25
Exhibited by matter as it undergoes changes in
composition.
e.g. hydrogen has the potential to ignite and explode given the right conditions
e.g. iron reacts with oxygen gas to form rust
CHEMICAL PROPERTIES
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Dependent on the amount of substance.
e.g. MASS β more substance, greater mass
e.g. VOLUME β more substance, greater volume
EXTENSIVE PROPERTIES
27
Independent on the amount of substance
e.g. DENSITY, Electrical Conductivity
INTENSIVE PROPERTIES
28
Way to Tell Intensive and Extensive Properties Apart
βͺ Take two identical samples of a substance and put them
together.
βͺ If this doubles the property (e.g., twice the mass, twice as
long), it's an extensive property.
βͺ If the property is unchanged by altering the sample size,
it's an intensive property.
29
- one or more substances are used up
- one or more new substances are formed,
- energy is absorbed or released
- IRREVERSIBLE
- e.g. burning of paper, cooking an egg, souring of milk
CHEMICAL CHANGE
30
- no change in chemical composition
- REVERSIBLE
- e.g. shredding paper, boiling of water, breaking a
bottle
PHYSICAL CHANGE
31
Variable Composition (e.g. 70%, 80% or 95% ethanol in water)
May be separated into pure substances by physical methods (e.g. distillation, filtration)
MIXTURE
32
Fixed composition (e.g. 100% ethanol)
Cannot be separated into simpler substances by physical methods
PURE SUBSTANCE
33
- Components are NOT distinguishable (single phase)
- Have same composition throughout (i.e. same amount
in any areas)
- e.g. SOLUTION
HOMOGENEOUS MIXTURE
34
- Components are distinguishable (multiple phases)
- Do NOT have same composition throughout (i.e.
different amount in various areas)
- e.g. SUSPENSION
HETEROGENEOUS MIXTURE
35
- Can be decomposed to simpler substance by
chemical changes
- consists of atoms of two or more different elements
bound together.
- e.g. water, H2O can be broken into hydrogen and
oxygen gases via electrolysis
COMPOUND
36
- Cannot be decomposed to simpler substance by chemical changes
- Consists of only one kind of atom
ELEMENTS
37
- The smallest unit that retains the properties of an element.
ATOM
38
- All matter is composed of atoms and these cannot be made or destroyed.
DALTONβS THEORY
39
The number of protons in the nucleus of
an atom determines its identity; this
number is known as the atomic number
of that element.
e.g.
- Hydrogen atom contains 1 proton.
- Lithium atom contains 3 protons.
ATOMIC NUMBER (Z)
40
The mass number of an atom is the sum of the number of
protons and the number of neutrons in its nucleus; that is
π΄πππ π΅πππππ = # ππ π + # ππ π
π΄πππ π΅πππππ = π¨πππππ π΅πππππ + π΅ππππππ π΅πππππ
MASS NUMBER (A)
41
Isotopes are atoms of the SAME ELEMENT with DIFFERENT MASSES
They are atoms containing the same number of protons but different numbers of neutrons.
ISOTOPES
42
Represents the composition of the nucleus
NUCLIDE SYMBOL
43
SAME MASS NUMBER - DIFFERENT ATOMIC NUMBER
ISOBARS
44
SAME NEUTRONS - DIFFERENT ATOMIC NUMBER
ISOTONES
45
Many elements occur in nature as mixtures of isotopes.
The atomic weight of such an element is the weighted average of the masses of its isotopes.
Atomic weights are fractional numbers, not integers.
ATOMIC WEIGHT
46
- Greek word βAtomosβ β uncuttable
- Atom as solid indivisible sphere
LEUCIPPUS AND DEMOCRITUS
47
- Matter is made up of four elements
ARISTOTLE AND OTHERS
48
- Solid Sphere (Billiard Ball) Model
- Atom as solid sphere but
NOT indivisible
DALTONβS ATOMIC THEORY
JOHN DALTON
49
DISCOVERY OF ELECTRONS
βͺ Elements of a chemical compound are held together by
electrical forces.
- Humphry Davy (1800s)
βͺ Relationship between the amount of electricity used in
electrolysis and the amount of chemical reaction that
occurs.
- Michael Faraday (1832)
βͺ βElectronsβ β Electric ions
- George Stoney (1891)
50
Elements of a chemical compound are held together by
electrical forces.
HUMPHRY DAVY
51
Relationship between the amount of electricity used in electrolysis and the amount of chemical reaction that occurs.
MICHAEL FARADAY
52
βElectronsβ β Electric ions
GEORGE STONEY
53
The Discovery of Electrons
1. CATHODE RAY TUBE
2. OIL- DROP EXPERIMENT
3. SATURN LIKE MODEL
54
The Discovery of Electrons
- Joseph John Thomson (1897)
- Most convincing evidence of electrons
- Plum pudding model
CATHODE-RAY TUBE EXPERIMENT
55
The Discovery of Electrons
- Robert Millikan (1909)
- Determine the charge of electrons
OIL-DROP EXPERIMENT
56
The Discovery of Electrons
- Hantaro Nagaoka (1903)
SATURN-LIKE MODEL
57
The Discovery of Protons
1. CANAL RAYS EXPERIMENT
2. SCATTERING EXPERIMENT
3. NUCLEAR MODEL
58
The Discovery of Protons
- Eugen Goldstein (1886)
- Cathode-ray tube also generates a stream of
positively charged particles
- These positive rays, or positive ions, are created
when the gaseous atoms in the tube lose electrons.
CANAL RAYS EXPERIMENT
59
The Discovery of Protons
- Ernest Rutherford (1910)
Assumption:
- If the Thomson model of the atom were correct, any
alpha-particles passing through the foil would have
been deflected by very small angles.
- Quite unexpectedly, nearly all of the a-particles
passed through the foil with little or no deflection.
Rutherfordβs Conclusion:
- Atoms consist of very small, very
dense positively charged nuclei
surrounded by clouds of electrons
at relatively large distances from
the nuclei.
SCATTERING EXPERIMENT
60
The Discovery of Protons
- Positive charge localized in the NUCLEUS
NUCLEAR MODEL
61
The Discovery of Neutrons
1. BOHRβ S MODEL
- BOHRβS PLANETARY MODEL
62
The Discovery of Neutrons
- Each orbit thus corresponds to a definite energy level
for the electron.
- When an electron is excited from a lower energy level
to a higher one, it absorbs a definite (quantized)
amount of energy.
- Electrons occupy only certain energy levels in atoms.
BOHRβS PLANETARY MODEL
63
Studied X-rays given off by various
elements.
H.G.J. MOSELEY
64
Bombardment of beryllium with high-energy alpha-particles produced NEUTRONS
JAMES CHADWICK
65
Described the electron of a hydrogen atom as revolving around its nucleus in one of a discrete set of circular orbits.
NIELS BOHR
66
- Proposed the idea of wave-like nature of electrons
βͺ Electrons can be treated as waves more effectively than
as small compact particles traveling in circular or elliptical
orbits.
LOUIS DE BROGLI
67
Based on the wave properties of matter
QUANTUM MECHANICS
68
- For electrons, it is not possible to determine the exact momentum and the exact position at the same moment in time.
WERNER HEISENBERGβS UNCERTAINTY PRINCIPLE
69
It estimates the position of electrons and quantifies energy levels.
ERWIN SCHRΓDINGERβS WAVE EQUATION
70
A region of space in which the probability of finding an electron is high.
ATOMIC ORBITALS
71
Erwin SchrΓΆdinger
- Electron Cloud Model
- Quantum Mechanical Model
MODERN ATOMIC MODEL
72
QUANTUM NUMBERS
1. Principal QN (π)
2. Orbital QN (π)
3. Magnetic QN (ππ)
4. Spin QN (ππ)
- for individual electrons only
73
βͺ π = π, π, π, β¦ (π)
βͺ Orbital β SHELL or ENERGY LEVEL
βͺ Distance of the electron
from the nucleus
βͺ Higher π, higher energy
PRINCIPAL QUANTUM NUMBER (n)
74
βͺ a.k.a. Azimuthal or Orbital Angular momentum Quantum
Number
βͺ π = π, π, π, π, β¦ (π β π)
βͺ Orbital β SUBSHELL/ SUBLEVEL
βͺ Shape of the orbital
- π = π s spherical
- π = π p dumb-bell
- π = π d clover leaf
- π = π f complex
ANGULAR/ORBITAL MOMENTUM QUANTUM NUMBER
75
βͺ ππ = βπ β¦ π β¦ + π
βͺ Orbital β Specific orbital
βͺ Orientation in space of the orbital
MAGNETIC QUANTUM NUMBER
76
βͺ For each INDIVIDUAL ELECTRON only
βͺ ππ = + π/π , - π/π
βͺ Direction of spin (clockwise or counter-clockwise)
βͺ Quantum Number and Electron Configuration
SPIN QUANTUM NUMBER
77
βͺ βDistribution of electronsβ
βͺ describes the number and arrangement of electrons in
orbitals, subshells and shells in an atom.
βͺ Ground state
- Atom in its lowest energy, or unexcited, state.
ELECTRON CONFIGURATION
78
- Orbitals fill in order of increasing energy, from lowest to highest.
AUFBAU PRINCIPLE
79
- No more than two electrons can occupy each orbital, and if two electrons are present, they must have opposite spins.
PAULI EXCLUSION PRINCIPLE
80
- The order of fill is the same but as you can see from
above the electrons are placed singly into the boxes
before filling them with both electrons.
- A single electron will occupy an empty orbital first
before pairing.
HUNDβS RULE
81
Arranged the periodic table based on chemical properties
DIMITRI MENDELEEV
82
Arranged the periodic table based on physical properties
LOTHAR MEYER
83
βͺ Both emphasized the periodicity, or regular periodic
repetition of properties with increasing atomic weight.
DIMITRI MENDELEEV AND LOTHAR MEYER
84
- βThe properties of the elements are periodic functions
of their atomic numbers.β
βͺ Vertical Columns β Groups or Families
βͺ Horizontal Rows β Periods
PERIODIC LAW
85
High electrical conductivity that decreases with increasing temperature
METALS
86
High thermal conductivity
METALS
87
Malleable, Ductile, silver luster, forms cat ions by losing electrons, form ionic compounds with non metals, solid state characterized by metallic bonding
METALS
88
Poor electrical conductivity
NON METALS
89
Good heat insulators
NON METALS
90
Brittle, non-ductile, no metallic luster, form anions by gaining electrons, form ionic compounds with metals and molecular compounds with non metals, covalently bonded molecules
NON METALS
91
- Show some properties that are characteristic of both
metals and non-metals
- Semiconductors
βͺ insulators at lower temperatures but become
conductors at higher temperatures
βͺ silicon, germanium, and antimony
METALLOIDS
92
PERIODIC PROPERTIES OF ELEMENTS
- Defined as half of the distance between the nuclei of neighbouring atoms in the pure element
- Expressed in Angstroms (1Γ
= 10-10 m)
ATOMIC RADII (size)
93
PERIODIC PROPERTIES OF ELEMENTS
- The energy required to remove an electron from a gas-phase atom
IONIZATION ENERGY (IE)
94
PERIODIC PROPERTIES OF ELEMENTS
- The energy change that occurs when an electron is attached to an atom in the gas phase to form an negative ion
ELECTRON AFFINITY (EA)
95
PERIODIC PROPERTIES OF ELEMENTS
- Measure of the relative tendency of an atom to attract electrons to itself when it is chemically combined with another atom
ELECTRONEGATIVITY (EN)
96
same mass no. different atomic no.
ISOBARS
97
same elements different mass no.
ISOTOPES
98
same neutrons different atomic no.
ISOTONES
