Introduction to Chemistry

Matter
the stuff of the universe
Matter
anything that has mass and takes up space
Mass
measurement that reflects the amount of matter
Weight
a measure of not only the amount of matter but also the effect of earths gravitational pull
Weight isnt always the same everywhere on earth.
It actually becomes less as you move away from Earths surface at sea level.
Much of matter and its behavior is Macroscopic.
Elements
made up of particles called atoms
Model
a visual, verbal, or mathematical explanation of experimental data.
Chemistry
the study of matter and the changes it undergoes
chemistry…

study of the structure and properties of matter

known as central science

-heat, enery, radio waves(not matter)

Mass does not vary with location

you use a balance to measure

units-kg,g,mg.

weight does vary…

uses a scale to measure

units-newtons, pounds

Scientific Method

a systematic approach used in scientific study

organized process for research

steps to scientific method

1.Problem-a question you want answered

2.observation-the act of gathering info-may be qualitative or quantitative

3.hypothesis-tentative explanation for an observation

4. Procedure-set of controlled observations that test the hypothesis(procedure used to collect data and must test one variable at a time)

5. Conclusion-tells whether the experiment supports your hypothesis or if your hypothesis needs to be revised

independent variable
the factor adjusted by the person doing the experiment
dependent variable
factor that changed because the person doing the experiment changed the independent variable
constant
factor that stays the same throughout the entire experiment
experimental group
group that undergoes the experiment or is tested
control group
the group that is used for comparison
theory
an explanation that has been supported by numerous experiments;broad principal of nature that has been supportes over time, and is subject to change
Scientific Law
relationship in nature that is supported by many experiments:considered to be fact
pure research
gaining knowledge for the sake of knowledge
applied research
reasearch undertaken to solve a specific problem
technology
the practical use of scientific info used to improve human life and the world around us
two substances that harm ozone and contain bromine
carbon tetrachloride and methyl cloroform
ozone
made of oxygen, a substance in the atmosphere that absorbs most harmful radiation before it reaches earths surface
substance
matter that has a definite and uniform composition
90% of earths ozone is spread out in a alyer that protects our planet
lowest layer of atmosphere…
troposphere
troposphere
contains the air we breathe:also where clouds occur and airplanes fly: all weather occurs  here
second layer of atmosphere…
stratosphere
stratosphere
extends from 10 to 50 kilos; ozone layer is located here
ozone formation
when oxygen gas is exposed to the ultraviolet radiation in the upper regions of the stratosphere, ozone is formed
ozone was first identified and measured in…
the late 1800’s
in 1920…
British scientist G.M.B. Dobson began measuring the amount of ozone in the atmosphere
chlorofluorocarbons..

substance that consists of chlorine, flourine, and carbon.

man-made, discovered by Thomas Midgely, nontoxic, stable, coolants, do not react with anything

in 1970…
scientists noticed that the number of CFC’s increased
Molina and Rowland
made the connection and hypothesized that CFC’s break down in the stratosphere due to interactinbg with the UV light from the sun. Then the chlrine particle produced by this interaction breaks down the ozone, therefore the ozone in the stratosphere is destroyed by CFC’s
Macroscopic
you do not need a microscope to observe it
quantitative data
data expressed using numbers
qualitative data
data expressed using the 5 senses