Chemistrychapter1 110912173446-phpapp01

1.1 What is Chemistry?
Chemistry: the study of the composition, structure, and properties
of matter, the processes that matter undergoes, and the energy
changes that accompany these processes
Speaking of which: what are we made of?
Lots of stuff- carbon, oxygen, hydrogen, sulfur, phosphorous, iron, nitrogen,
to name just a few. The human body is composed of many hundreds of millions of
chemical compounds and substances, each just a differing arrangement of elements
from the periodic table.
But where do these things come from?
All of the elements come from the stars, and were made many billions of years ago
through the coagulation of interstellar dust.
How are the elements formed?
In a process called fusion, but we’ll get to that later.

Branches of Chemistry
There are several areas of study and research in chemistry which often
overlap with one another. So put on your fun hats, here we go:
1. Organic Chemistry: the study of most carbon-containing compounds
(more on this later as we will begin organic at the end of the year)
2. Inorganic Chemistry: the study of (duh) non-organic substances which have
organic fragments bonded to metals (organometallics)
3. Physical Chemistry; the study of the properties and changes of matter and their
relation to energy.
4. Analytical Chemistry: the ID of the components and compounds of materials.
5. Biochemistry: the study of substances and processes occuring in living things.
6. Theoretical Chemistry: the use of mathematics and computers to understand
the principles behind observed chemical behavior and to design and
predict the behavior of new chemical compounds.

Chemistry
organic
chemistry
inorganic
chemistry
analytical
chemistry
physical
chemistry
bio-
chemistry

1.2 Matter and It’s Properties
Matter anything that has mass and takes up space (volume)
and so…
Mass measure of the amount of matter.
Atom: smallest unit of an element that
maintains the chemical identity of
that element.
Examples?
A carbon atom.

Element: a pure substance that cannot be broken down into
simpler, stable substances and is made up of one type
of atom.
Examples?
The element carbon.
For a complete list of elements, where should we look?
More on this later.

Compound: a substance that can be broken down into simple,
stable substances. Each compound is made from atoms
of two or more elements that are chemically bonded.
Examples?

Properties and Changes in Matter
Every substance has characteristic properties.
Properties are either Extensive or Intensive
Extensive Properties: depend on the amount of matter
present.
Examples: mass, volume, amt. of energy
Intensive Properties: do not depend on the amount of matter present.
Examples: melting point, boiling point, density.

Physical Properties and Physical Changes
Physical Property: a characteristic that can be observed or measured
without changing the identity of the substance.
Examples:
Boiling point (temp. substance goes from liquid to gas)
Melting point (temp. substance goes from solid to liquid)
Freezing point (temp. substance goes from liquid to solid)
Condensation point (temp. substance goes from gas to liquid)
By the way, what is the boiling point of water? Freezing point?
The melting point? Condensation point?

Physical Properties and Physical Changes
Physical Change: a change in substance that does not involve a
change in identity of the substance.
Examples:
Grinding, cutting, melting, and boiling a material.

Quick Review!
Fill in the blanks with any of the new terms you
just learned …
• I am an astronaut going to the moon and I’m bringing a scale
with me. In space, I will stand on the scale and find that my
_______ will be the same but my ______ will have changed.
• The graphite in my pencil is only made up of carbon, therefore it
is an ________. The rest of my pencil is made up of several
things, which makes it more like a _________.
• Water always freezes at 0°C. This is a _______ property (hint:
there are two correct answers!)
• Cutting a piece of paper in half gives me two smaller pieces of
paper. Each piece is still has the same chemical characteristics
but has less mass. This is called a _______ change.

Change of State:
Physical change of substance from one state to another.
Solid: matter in this state has a definite volume and shape.
Liquid: matter in this state has definite volume but indefinite shape.
Gas: matter in this state has neither definite volume or shape.

Change of State:
Physical change of substance from one state to another.
An important 4th
state of matter is something called
Plasma: high temperature physical state of matter in which atoms
lose most of their electrons.

Change of Phase:
When a substance goes from one form to
another, (almost) always in the same order.
solid liquid gas
This goes for all substances, remember.
Now, some terms.
HEAT HEAT
- HEAT - HEAT

Change of Phase (for water):
solid liquid gas
MELTING BOILING
FREEZING CONDENSING
0ºC 100ºC
melting/freezing point boiling/condensation point
(ice) (steam)(water)

Chemical Properties and Chemical Changes
Chemical Property: a substances ability to undergo changes that
that transform it into different substances.
Examples:
Rusting material-
Iron + Oxygen (g) Iron oxide (rust)
(before)
(after)

Chemical Properties and Chemical Changes
Chemical Change: a change in which one or more substances are
converted into different substances.
Reactants Products
Reactants: the substances that react in a chemical change
Products: the substances that are formed in a chemical change.
C + O CO2

Quick Review!
• Fill in the blanks with any of the new terms
you just learned …
• There are three main phases of matter, they are
_____, ______, and ______.
• When the ice cube in my drink melts, it is
considered a _____________.
• I will make Ms. T so proud by NEVER forgetting
that the freezing/melting point of water is _____
and the boiling/condensation point is _____.
• When iron combines with oxygen, iron oxide, or
rust, is produced. This is a ________. Iron’s ability
to undergo this reaction is called a _________.

Development of the Periodic Table
The modern periodic table of elements is mostly the work of Russian chemist
Dmitri Mendeleev (1834-1907). It was set up in such a way so group elements
in columns according to their properties, but also put them in ascending order
according to their atomic number. Let’s observe:
The vertical columns are called groups; the horizontal rows are called periods.
Periodic Law: when elements are arranged in order of increasing atomic number,
there is a periodic repetition of their physical & chemical properties.

The vertical columns are called groups, or families.
There are 18 groups on the periodic table.
Groups

The horizontal rows are called periods.
Periodic Law: when elements are arranged in order of increasing
atomic number, there is a periodic repetition of their physical &
chemical properties.

Periodic Trends
Elements in the same group: physically and chemically similar
Elements in the same period: ordered in increasing size and atomic
number.

Metals
Characteristics of metals: excellent conductors of heat and electricity, very reactive,
usually make positive ions when dissolved in solution, mix well to make alloys.

Alkali Metals
Group 1A: Li, Na, K, Rb, Cs, Fr. Does not include hydrogen.
▪ They are very reactive because of the lone electron in their outer shell.
▪ Very shiny and light in weight.
http://www.youtube.com/watch?v=OFG4Yr7lQzw&feature=related
http://www.youtube.com/watch?v=uqDWbknpiVk&feature=related

Alkali Earth Metals
Group 2A: Be, Mg, Ca, Sr, Ba, Ra
▪ Not as reactive as alkali metals, but form bonds very easily.

Transition Metals
Have a special electron shell arrangement where two of their outer shells
are not full. This allows them to bond to many other elements in a
variety of shapes.

Halogens
Have an outer shell that is almost full, therefore very reactive. Often bond
with metals and elements from group one (alkali metals). When an halogen
combines with another element, the resulting compound is called a halide.

Inert Gases (Noble gases)
Include: He, Ne, Ar, Kr, Xe, Rn.
Have a full outer shell and are very unreactive, hence the title “inert”.

Lanthanide Series
· Also known as rare-earth or inner-transition elements.
· Fifteen elements that start with lanthanum (La) at atomic number 57
and finishing up with lutetium (Lu) at number 71

Actinide Series
· These elements are all radioactive and only some are found in nature;
some elements with higher numbers have only been made in labs.
·Fifteen elements that start with actinium (Ac) at atomic number 89 and
finishing up with lawrencium (Lr) at number 103

Metalloids
Metalloids are found on the periodic table
between the metals and non-metals.
Appropriately, they exhibit characteristics of both metals and non-metals.

Nonmetals
Many nonmetals are gases at room temperature: N; O; F; Cl.
These are elements that are poor conductors of heat and electricity.

Chemistrychapter1 110912173446-phpapp01

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