What you need to know in Chemistry
The
Important Basic Topics
Listed
below are some of the more important topics that you should be familiar with.
You may, of course, review or study as much as you like, but you are encouraged
to concentrate on and become familiar with the following topics:
1. Metric System. Be familiar with the units of mass, length,
and volume in the metric system. A separate page covers this important topic.
2. Temperature Scales. Be familiar with the Celsius (centigrade)
and the kelvin (absolute) temperature scales.
3. Symbols of the Elements. You should be familiar with the
symbols for elements with atomic numbers 1-38, 46-56, and 78-83. The symbols
are usually abbreviations of either the English or Latin name of the element.
Although you will have a periodic table for all exams, the more familiar you
are with the symbols, the better off you will be.
4. Chemical Formulas. You should become familiar with
the way in which the symbols of elements are combined to give chemical formulas
for neutral (uncharged) molecules and positive or negative ions, such as SiCl4,
CaF2, SO4-2, etc.
5. Chemical Equations. You should understand how chemical
formulas are combined to give chemical equations, which describe chemical
changes.
6. Atomic Structure. You should have at least a rough
idea of the structure of the atom. Be aware that the nucleus, composed of
protons and neutrons, is the massive (but tiny) positively charged central core
of the atom. It is surrounded by one or more negatively charged electrons which
occupy most of the volume of the atom but contribute only a tiny fraction of
its mass. You should also know what isotopes are.
7. Weight Relationships. You should know what atomic
number, atomic mass number, atomic weight, formula weight, and molecular weight
mean. Understand what gram atomic weight, gram formula weight, and gram
molecular weight mean. Know what is meant by a mole of a substance, and
understand the relationship between the mole and Avogadro's constant.
8. Concepts from Physics. Have some notion of the meaning of
force and energy and the units in which they are measured in the Standard
International (SI) system of units. Pressure is a measure of force per unit
area; common units of pressure are pascal (Pa), atmosphere (atm), and torr
(Torr).
9. Concentrations. Know some common ways of expressing
concentration, such as weight percent and moles of solute per liter of solution
(molarity).
Review
these topics, and check out the page covering Dimensional Analysis and Units.
A review of certain topics in high school
mathematics will also be valuable to any student in chemistry. Listed below are
some of the topics with which you should be quite comfortable.
1. Calculators. You must have a calculator and know how to
use it for multiplication, division, taking square roots, finding logarithms
and antilogarithms (both base-10 and natural, or base-e, logs), and using
exponential notation.
2. Exponential Notation. Be thoroughly familiar with
exponents, and be able to multiply, divide, raise to powers, and take roots of
numbers with exponents. Understand the relationship between exponents and
logarithms, and be able to work with logarithms, both base 10 and base e. Know
the SI prefixes for common multiples of powers of 10, such as "m" for
"milli-" or "k" for "kilo-" and so forth.
3. Linear Equations. Be able to recognize an equation for a
straight line, and know how to recognize the line's slope and intercept in the
equation.
4. Algebra. Be able to solve a system of two simultaneous
linear equations in two unknowns.
Many of the
definitions and concepts mentioned above will be reviewed quickly during the
initial weeks of Chemistry. However, it will be to your advantage to have seen
such material and thought about it in advance.
