Chemistry and Nature of Science
Chemistry is the study of...
matter and how it changes
The shortcut method for writing very small numbers or very large numbers.
Scientific Method
Difference between accuracy and precision
Accuracy - how close a measurement is to the actual answer
Precision - how close a measurement is to other measurements of the same thing
What is the rule when multiplying or dividing?
Answer must have the same amount of significant figures as the measurement with the fewest amount of significant figures.
Kilo- means...
1,000 times
Matter is anything that has....
mass and volume (takes up space)
Write an example of a number written in scientific notation and standard notation.
5.4 x 10^6
5,400,000
What number(s) of this measurement is uncertain? 124.84
4
What is the rule when adding or subtracting?
The answer must have the same amount of significant figures to the right of decimal point as the measurement with the least amount of significant figures to the right of the decimal point.
500 mg = _____ g
0.5 grams
Difference between Qualitative and Quantitative answers
Qualitative - Describing something with out using numbers. Quantitative - Describing something using numbers.
245,860,000,000
Write in Scientific Notation
2.4586 x 10`11
How many significant figures are in the measurement 30,780 grams?
4
8.35 meters x 3.996 meters
33.4 square meters
2.5 km = ______ cm
250,000 cm
What is the formula for finding Percent Error
Percent Error= error/accepted value x 100
2.65 x 10 ^-12
Write in Standard Notation
.00000000000265
How many significant figures are in the measurement 3050.1 grams?
5
98.0 kilograms - 1.22 kilograms
96.8 kilograms
Calculate the density of an object with the mass of 24.3 grams and the volume of 32.9 mL.
.739 g/mL
Difference between independent and dependent variable
Dependent - responds to the independent variable Independent - changed by the experimenter
What does a negative exponent tell you about a number?
The number is very small. (Much smaller than 1)
A tree is 70 feet tall. It was measured twice using the same tool. The measurements recorded were: 59.3 feet, 59.5 feet, and 58.9 feet. Are these measurements accurate, precise, or both?
Precise
7 centimeters x 1.86 centimeters x 0.002 centimeters
0.03 cubic centimeters
What is the volume of an object with the density if 1.25 g/mL and the mass of 281 grams?
225 mL