Exam 1 Flashcards
(116 cards)
Are pure substances visible to our naked eye?
No, we talk about it at the submicroscopic level
Are Mixtures visible to our naked eye?
Yes, we talk about it at the microscopic level
What are the two types of pure substances?
Elements and Compounds
What are the two types of mixtures?
Heterogeneous or Homogeneous
What is the difference between an elements and a compound?
An Element is a singular composition of matter (elements form the periodic table)
A compound is made up of these elements
What is the difference between a homogeneous and heterogeneous mixture?
Homogeneous is a mixture that has a uniform appearance.
EX: salt and sugar
Heterogeneous is a mixture that has a visible variety of substances
EX: salt and pepper
What are the types of properties?
Physical and chemical
What is part of a physical property?
it can include appearance, density, solubility, freezing point, boiling point
How do we know a property is physical?
Physical properties do NOT change the identity of the substance
What is part of a chemical property?
Flammability and Reactivity
What determines a property as a chemical one?
Chemical changes convert one substance into another
What type of measurement system do we use in science?
The Metric System
In sig figs ________ always count
Integers
Do zeros in between 2 integers count? Provide an example
Yes, zeros in between two integers ALWAYS count
ex: 12,004
Do zeros in the beginning of a number count? Provide an example..
No, zeros in the beginning of a number NEVER count
ex: 0.000015
Zeros at the end only count if and only if…
there is a decimal
ex: 1,200.56
What do we know about zeros that are at the end but before a decimal?
We are unsure of whether or not they count
ex: 100
When calculating sig. figs, (addition and subtraction), what are the rules?
Your final answer can only have as many decimal places as the least exact measurement.
ex: 3.18 + 0.01315 means your answer can only have 6 decimal places since 0.01315 is the LEAST exact measurement
When calculating sig. figs, (multiplication and division), what are the rules?
Your final answer can only have as many SIG FIGS as the least exact measurement.
ex: 203 * 0.0048 means your answer can only have 2 sig figs since 0.0048 has the LEAST exact measurement.
What contents are in scientific notation?
It contains a coefficient and an exponential notation (*10 ^ x)
If the exponent in the notation is positive, where do we move the decimal?
to the right
If the exponent in the notation is negative, where do we move the decimal?
To the left
What are the 3 conversion factors for grams?
1 kg = 1000 g
1mg = 0.001 g
1000 mg = 1 g
How do you convert from Celsius to Kelvin?
K= Celsius + 273