Flashcards in Chapter 1 - Chemistry And Measurements Deck (56):
Study of composition, structure, properties, and ex of matter
Branches of chemistry
All substances that make up our world
Study of composition, properties, and reaction of matter
Study of substances that contain the element carbon
Study of the chemical reactions that takes place in biological systems
Who were the early chemists?
What did early chemists study, and do?
Extracted metals from ore
designed some of the first lab equipments
Developed early lab procedure
Substance that has the same composition and properties wherever it is found. Aka substance
What are the units of measurements?
Length, volume, mass, temperature, and time
Amount of space a substance occupies
Metric: liter (L)
SI: cubic meter (cm^3)
2.54cm. 1 in
1L. 1.06 qt
946 mL. 1 qt
1000L. 1 m^3
Measure if the quantity of material it contains
SI unit. Kilogram (kg)
Metric unit. Gram (g)
What is the difference between weight and Mass? (Define weight)
Weight is the measure of the gravitational pull of an object.
Measures how hot/cold a substance is
Time metric unit
Seconds (s) for both metric and SI
What does a scientific notation equation consist of?
Coefficient, a power of 10, and a unit of measurement
define measured numbers
Numbers you obtain when you measure a quantity using a measuring tool. These numbers are uncertain.
Are non zero numbers significant? ex) 2.5 (How many significant figures?)
Are zeros at the end of a decimal significant? ex) 21.00 (How many significant figures?)
Are zeros between nonzero numbers significant? ex) 2.05 (How many significant figures?)
Are coefficients in a scientific notation equation significant? ex? 5.70 x 10^2 (How many significant figures?)
Are zeros at the beginning og a decimal number significant? Ex) 0.004 (How many significant figures?)
Are zeros used as a place holder in large numbers significant? Ex) 25,000,000
How many significant figures?
5.00 x 10^3
4 x10 ^2
5.00 x 10^3 : 3
16.00 : 4
0.0040 : 2
4 x 10 ^2 : 1
What are exact numbers?
Numbers obtained by counting items, are not measured
When do you drop numbers when rounding significant figures?
if the first digit to be dropped is 4 or less then all the following digits are simply dropped.
When do you round up significant figures?
If the first digit to be dropped is 5 or greater then the last retained number is increased by 1.
Round these to 3 and 2 significant figures:
-2SF: 3.3.x 10^3
What is/are the rule(s) for rounding off significant figures in multiplication and division?
The final answer is written so it has the same number of significant figures as the measurement with the fewest significant figures.
What is/are the rule(s) for rounding off significant figures for addition/subtraction
the final answer has the same number of decimals as the measurement with the fewest decimals
What are the prefixes that increase the size of a unit?
peta, tera, giga, mega, kilo
What are the prefixes that decrease the size of a unit?
deci, centi, milli, micro, nano, pico, femto
What is equality?
Equality shows the relationship between two units that measure the same quantity. (same length, different units)
What is a cubic centimeter?
Volume of a cube with dimensions of 1 cm on each side, 1cm^3 has the same volume as mL
parts per million (mg/kg)
parts per billion (mg/kg)
Formula for density?
Mass of substance/ volume of substance
when will a substance float in water?
it it is less dense than water.
when will a substance sink in water?
If it is denser than water.