Studied by 1 personChemistry
The study of the composition, structure, properties, and reactions of matter
Industries that chem is used for
Pharmaceutical Industry
Food Science
Forensic Sciences
Medical Practitioner
Construction + Automotive Industry
How often does chemistry occur
All the time! All around you
Matter
All the substances that make up our world
Water, air, a glass
What does all matter have?
Mass and Volume
Mass
Amount of matter the substance has
Volume
Space that the matter occupies
Basic air make-up
80% Nitrogen
20% Oxygen
What is the simple N and O called?
Atomic nitrogen and oxygen
What does the N₂ and O₂ mean?
It means that 2 of that atom has bonded together
What is molecular nitrogen?
How nitrogen exists in nature
Is electricity matter?
Nope; the current are not matter
Is car exhaust matter?
Yes; it has many chemicals and stuff
Are atoms matter?
Yes; smallest unit of matter
Is wind matter?
No; it’s formed by interacting matter, but the energy of wind is not matter
Is democracy matter?
No; it doesn’t take up space, except in brains-
Are UV lights matter?
No; any type of visible light isn’t matter = energy
Chemicals
Substances w/ the same composition and properties wherever found
Examples of chemicals
H₂O = Water
Au = Gold
Which ones have chemicals?
Sunlight
Fruit
Milk
Breakfast Cereal
Fruit, Milk, and Breakfast Cereal
Sunlight = not matter
Scientific Method
A set of general principals that helps to describe how a scientist thinks
State and describe the steps of the scientific method
Make Observations about nature and ask questions about those observations
Propose a Hypothesis: a possible explanation of an observation or law
Perform Experiments: find relationships between hypothesis and observations
Make a Conclusion as to whether the hypothesis was true or false after experiments + analysis
What can be done if an observation is always true?
It may be stated as a law
What do you do if your hypothesis and experiment don’t match up?
Revise your hypothesis and try again
What can a conclusion lead to?
A theory
What is the place value of each: 2518.407
2 = thousands
5 = hundeds
1 = tens
8 = ones
4 = tenths
0 = hundredths
7 = thousandths
How do you write a negative number?
With a negative sign → -7
Solve:
3 + 5 =
3 + (-5) =
-6 + (-8) =
5 - (-7) =
5 x (-4) =
-7 x (-2) =
-28/ -2 =
36/-6 =
3 + 5 = 8
3 + (-5) = -2
-6 + (-8) = -14
5 - (-7) = 12
5 x (-4) = -20
-7 x (-2) = 14
-28/ -2 = 14
36/-6 = -6
Percentage Calculation Formula
part / whole(total) x 100 = % of part to the whole
There are 19 red posters, 5 yellow posters, and 8 purple posters. What is the percentage of purple posters?
19 + 5 + 8 = 32
8/32 = 0.25
0.25 x 100 = 25
25% purple posters
Solve for x:
y = 4x + 7.8
y = 4x + 7.8 → subtract 7.8 y - 7.8 = 4x
y - 7.8 = 4x → divide by 4
x = (y - 7.8)/4
Solve for T₂:
V/T = V₂/T₂
Cross multiply → VT₂ = V₂T
divide by V to get T₂ alone
T₂ = V₂T/V
What are the parts of a graph
x-axis = horizontal
y-axis = vertical
Title = description of graph
Points = data values
What is it called when the x and y both increase on a graph?
Direct relationship
What is scientific notation used for?
To write very large and very small numbers
How do you set up scientific notation
co-efficient x power of 10
What does the co-efficient have to be?
Between 1 and 9.999999(repeating)
Write in scientific notation:
2400
0.00086
569
2400 = 2.4 x 10³
0.00086 = 8.6 x 10⁻⁴
569 = 5.69 x 10²
In A Scandal in Bohemia, Sherlock Holmes receives a mysterious note. He states, "I have no data yet. It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." What do you think Holmes meant?
Holmes meant…
Theories should be made to support fact; facts should not be re-written/worded to fit theories
You cannot make any assumptions before having data/facts to support it
Classify each of the following as an observation, a hypothesis, an experiment, or a conclusion:
a. The bicycle tire is flat
b. If I add air to the bicycle tire, it will expand to the proper size
c . When I added air to the bicycle tire, it was still flat
d . The bicycle tire has a leak in it
a. observation
b. hypothesis
c. experiment
d. conclusion
How will each of the following increase your chance of success in chemistry?
a. self-testing
b. forming a study group
c. reading an assignment before class
a. Assessing yourself can help you locate flaws and areas that you need to study more. It can help with pacing if you plan to time yourself.
b. Forming a study group will let you get different perspectives on topics, and may also motivate you to study more. Studying with people can also be a great way to ask questions using the insight of others.
c. Reading an assignment before class can help refresh your memory and prepare you for whatever task you need to complete that day.
How will each of the following decrease your chance of success in chemistry?
a. studying only the night before an exam
b. not going to class
c. not practicing the problems in the text
a. Studying only the day before will not help you retain the information nor will it be able to assist you in the future.
b. Not going to class can mean you miss important information. You won’t learn anything if you don’t at least show up.
c. Not practicing may leave you with unresolved questions that you won’t know you have until you do the problems yourself.
Note
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