Unit 1: Chemical Foundations Flashcards
What is the definition of chemistry?
The natural brand of sciences dealing with the composition, properties and reactions of matter using micro and macroscopic perspectives.
What are the 3 branches of chemistry?
- Physical Chemistry
- Inorganic Chemistry
- Organic Chemistry
What are the 2 goals of chemistry?
Accuracy and Precision
What is accuracy?
Accuracy is the level to which the experimental/determined value agrees with a known/theoretical value
How is accuracy measured and what is the formula for it?
-Using percent error
- [(exp-theo)/theo] * 100%
What should the percent error be for high school students?
It should be less than or equal to 10%
What is an example of accuracy?
The closer an arrow is to the center of a dartboard, the more accurate it is
What is the definition of precision within a set of numbers?
The smaller the difference within a set, the higher the precision
What is the definition of precision with regards to tools?
- The smaller the window for error in a tool, the higher its precision
- In measurement tools, the precision is indicated by plus or minus half the smallest unit available
What is the definition of precision within individual measurements?
As indicated by significant figures, the greater the number of sig. figs, the greater the precision
What is the scientific method?
A systematic process with one input variable, and one output variable, while all the other variables are controlled
List the steps of the scientific method
- ask a question
- form an hypothesis
- design an experiment
- do an experiment
- make observations
- analyze
- draw a conclusion
Why is creativity important in the scientific method?
It is important when asking a question, forming an hypothesis, finding observations and forming a conclusion.
What makes a good experiment?
- It would be a slow and systematic process
- You have to identify the variables
- Be clear on what you are ultimately measuring
What is an experiment?
Something that involves a new input variable
What is a trial?
- A change in the level of the independent variable involved in an experiment
- Often 7 trials are done in an experiment
What is a test?
- A repeat of a trial to ensure reliability of the data.
- Often 3 tests are done for each trial and the average is considered the true value
What are the 2 types of observations?
Qualitative and quantitative
What is a qualitative observation?
An observation related to the quality of the objects in question. They are stated in full sentences and they don’t have measurements
What is a quantitative observation?
An observation related to the quantity of the objects and is the actual measurements of the objects in question.
What is a significant figure?
A number that communicates a magnitude with certainty
What is scientific notation?
A standardized method of representing the sig. figs of a given measurement using powers of ten
What are the 7 fundamental quantities and their units?
- mass (g)
- time (secs)
- temperature (kelvin)
- length (meters)
- amount of substance (mol)
- electric current (amperes)
- luminous intensity (candela)
What is a derived unit?
A unit formed by the combination of one or more fundamental units
State 3 derived units
- volume (cm^3)
- density (g/mL)
- force (kg m/s)
What are the 2 modes volume can be measured by?
Capacity mode and Cubic mode
State 3 units in capacity and cubic mode and what they are used to measure
Cubic mode: used for solids
- cm^3
- dm^3
- m^3
Capacity mode: used for fluids
- mL
- L
- kL
1cm^3 = 1 __L
1dm^3 = 1 __L
1 m^3 = 1 __L
1cm^3 = 1 mL
1dm^3 = 1 L
1 m^3 = 1 kL
List the prefixes from tera- all the way to pico- with their unit and power of ten
Tera - 10^12 - T
Giga - 10^9 - G
Mega - 10^6 - M
KIlo - 10^3 - k
Hecto - 10^2 - h
Deca - 10^1 - da
Deci - 10^-1 - d
Centi - 10^-2 - c
Milli - 10^-3 - m
Micro - 10^-6 - μ
Nano - 10^-9 - n
Pico - 10^-12 - p
What is the size of an atom and what is it called
It is called an Angstrom (Å) and it is 10^-10
