sces1200 l01 introduction to matter
TRANSCRIPT
Principles of Chemistry(Prinsip-Prinsip Kimia)
An Introduction
Composition of the Course
30% Continuous Assessment 15%
70% Physical 35%
Stoichiometry and Periodical table
35%
Total 100%
DURING THE COURSE
FINAL EXAMINATION
Overview
๏ Atom: history of atom, theories, atomic structure, classical and
quantum mechanic, discrete energy concept, electron
configuration
๏ Gas: gas properties, real gas and perfect gas, related equations
๏ Stoichiometry
๏ Periodical table
๏ Lecture notes provided online at: www.kelalangkon.blogspot.com
What is Chemistry?
๏ Chemistry (a word derived from “alchemy”) is the
science of matter at or near the atomic scale.
๏ Chemistry deals with the composition and
properties of such structures, as well as their
transformations and interactions.
MatterA Revision
States of Matter
Laws on Matter
๏ Law of Conservation of Mass / Matter: states that matter
changes form, but cannot be created or destroyed. -
thermodynamic, kinetics, equilibrium
๏ Law of Definite Proportions / Constant Composition: states that,
in a pure compound, the elements combine in definite
proportions to each other by mass. - stoichiometry
๏ Law of Multiple Proportions: states that when element combine,
they do so in a ratio of small whole numbers. - stoichiometry
๏ Intensive property of a system is a physical property of the
system that does not depend on the system size or the
amount of material in the system.
๏e.g. temperature, boiling & melting points, density
๏ Extensive property of a system does depend on the system
size or the amount of material in the system.
๏e.g. mass, volume, energy, heat capacity
Properties of Matter
WHAT ARE THE EXAMPLES OF PHYSICAL AND CHEMICAL PROPERTIES?
Physical properties Chemical properties
H2Colourless, Odourless
M.p.: -259°C, B.p.: -253°C• Flammable
O2Colourless, Odourless
M.p.: -219°C, B.p: -183°C• Supports combustion • Oxidising agent
H2OColourless, OdourlessM.p.: 0°C, B.p.: 100°C
• Non-flammable • Does not support combustion
2H2 + O2 2H2O
Definition and Classification๏ Matter is all that have mass and occupy space.
MATTER
MATERIAL MIXTURE
COMPOUNDSELEMENTS HOMOGENEOUS HETEROGENEOUS
MOLECULES
ATOM
ANY THINGS SMALLER THAN AN ATOM?
EnergyEnergy and persistence conquer all things.
-Benjamin Franklin-
Definition and Type of Energy
Law of Conservation of Energystates that energy can be converted from one form to another, but it
cannot be created or destroyed
Note: similarity in the laws of conservation of mass and of energy
TYPES OF ENERGY- KINETICS- POTENTIAL- HEAT - RADIATION - SOUND - MECHANICAL - CHEMICAL - NUCLEAR- ELECTRICAL
Definition
๏ ability to do work
๏ potential for causing changes
๏ does not occupy space
Kinetic and Potential Energies
๏ Kinetic energy is energy that a body possesses as a result of its motion. It is formally defined as the work needed to accelerate a body from rest to its current velocity.
๏ Potential energy which depends on mutual positions of bodies. The energy is defined as a work against a specific force such as gravity, an elastic force of a spring in a clockwork motor, electric force, etc (and is usually named after that specific force).
ME = ½MV2
E = MGH
H
M
Einstein and Atomic Bomb
๏ 1905, as part of his Special Theory of Relativity, E = mc2 ๏ 1929, "unconditionally refuse to do war service, direct or indirect... regardless of how
the cause of the war should be judged." ๏ 1941, Bush didn't trust Einstein to keep the project a secret: "I am not at all sure...
[Einstein] would not discuss it in a way that it should not be discussed." ๏ 1946, "I have always condemned the use of the atomic bomb against Japan.“๏ 1954, "I made one great mistake in my life... when I signed the letter to President
Roosevelt recommending that atom bombs be made; but there was some justification - the danger that the Germans would make them."
AtomThe Building Block of Matter
What is Atom?
๏ Isotope: same atomic number, different mass number
(different numbers of neutron)
๏ Mass: centered at the nucleus
๏ nucleus (proton & neutron)
๏ Proton: determine chemical elements
๏ Neutron: determine isotope of an element
๏ Mass: centered at the nucleus
๏ Proton: determine chemical elements
๏ Neutron: determine isotope of an element
๏ Electron: negatively charged, set at different energy levels (orbitals),
determine chemical properties
๏ Isotope: same atomic number, different mass number (different numbers
of neutron)
๏ Electron: negatively charged, set at different energy
levels (orbitals), determine chemical properties
Revolutionary of Atom
Democritus (Greek) defines atomos as smallest possible
individual particle
1900
NOW
400 BC
1600
Quantum Theory: Thomson (1903) Rutherford (1911), Bohr (1913),
Schrödinger (1923), Chadwick (1932)
Industrial revolution – deepest meaning of atom by advanced
method (Classical theorem)
Quantum Dots, Nanotechnology
Femtotechnology?
Abandon of Isotope
Atomic Mass Scale
๏ Unit for mass of atom is referred to as atomic mass unit (amu)
๏ Standardized against atomic mass of 12C - as 12 amu
i.e. 1 amu = atom mass of 12C
๏ Examples:
๏ 12C – 12.0000000 amu
๏ 13C – 13.0033548 amu
๏ 16O – 15.9949146 amu
๏ 17O – 16.9991360 amu
๏ Also known as relative atomic mass
Atomic Mass Unit
๏ Average of the atomic masses of all the chemical element's isotopes as found in a particular environment, weighted by isotopic abundance.
๏ Example: carbon (with 2 isotopes C and C)
๏ 12C : 98.892% x 12.0000000 = 11.8670 amu
๏ 13C : 1.108% x 13.0033548 = 0.1441 amu
12.0111 amu
LET’S TRY WITH O (THREE ISOTOPES)…!16O (15.9949)17O (16.9991)18O (17.9991)
Energy
HOW DOES IT “LOOK”?
Mole
HeatForce
Electronegativity
Bonding
Avogadro number
Individual Assignment
๏ Task: Compile at least 5 profiles of individual that contribute strongly to the finding of atom and its components. Describe their backgrounds and contribution to science.
๏ Format: Arial, 11 pts, not more that 5 pages A4 paper
๏ Dateline: submit before 26 January 2010
๏ E-mail to: [email protected] or [email protected] (please put subject as “SCES/P 1200 Assignment”