Chemistry Pre Comp Flashcards
What is the scientific method?
The scientific method is based on continued observation and experiment
What is scientific law
The scientific law summarizes a series of related observations
What is a liquid?
A liquid has definite volume and no definite shape
What is a gas?
A gas has no definite shape and no definite volume
What is an element?
A substance that can’t be chemically broken down into a
simpler substance
What is decanting?
Separating a solid from a liquid by pouring off the liquid
What is filtration?
Filtration is pouring a mixture through a filter paper to separate the solid from the liquid
What is a homogeneous mixture?
A combination of two or more substances in a variable proportion where the composition is constant throughout
What is heterogeneous mixture?
A combination of two or more pure substances in which the original substances retain their chemical properties.
What is physical change?
Physical change is change in form and not atomically structure
How is density calculated?
Density is mass/volume.
What are the rules for determining number of significant figures?
1) Zeros between numbers count
2) Zeros to the right of numbers count
3) Zeros to the left of numbers do not count
4) All non-zero numbers count
What are the rules for correct number of significant figures when measuring?
Include all known digits plus one estimated digit
What are the rules for correct number of significant figures when adding or subtracting?
The answer can contain no more decimal places than the least accurate measurement. (e.g., 19.23 + 0.4745 + 127.2 = 146.9)
What are the rules for correct number of significant figures when multiplying or dividing?
The answer can have no more sig figs than the least accurate number. (e.g., 9.13 x .07545 =0.689)
