Chemistry mid-year term Flashcards
What is matter?
Anything that has mass or volume
What is an element?
Pure form of matter-cannot be broken down.
What is a compound?
Combination of 2 or more atoms of different elements chemically combined in a fixed ratio.
What is a mixture?
2 or more substances mixed together, Not chemically combined.
What are pure substances?
A substance/matter made up of the same type of atom-contains a fixed ration.
What are diatomic elements?
2 atoms of the same element combined.
What is a solid?
State of matter that has a fixed shape/volume.
What is a liquid?
State of matter that has a fixed volume but no fixed shape.
What is a gas?
State of matter that has no fixed volume or fixed shape.
How can we predict the phase of a substance at a given temperature?
Looking at its Boiling/Melting point
What is a chemical formula?
Indicates the elements and their properties in a compound.
How do we indicate the phase of matter in a chemical formula?
By putting a subscript of (s), (L), (G) to represent its phase.
What do the coefficients and subscripts represent in a chemical formula?
The coefficient represent how many molecules there are. The subscript represents how much of each elements there are.
What is a physical properties?
A property that can change without changing the chemical composition.
What is a chemical properties?
A property that can only be changed by changing the chemical composition.
What is a physical change?
A change that does not affect the chemical composition.
What is a chemical change?
A change that changes the chemical composition.
Filtration
Based on particle size. Separates undissolved solid/liquids.
Magnetism
Separates metals in a mixture base on magnetic activity.
Distillation
Separates liquids based on boiling points.
Crystallization
Liquid evaporates and solids crystallize. Separating solids/liquids.
Chromatography
Base on solbility.
Decantation
Pour the liquid out.
What is the general format for scientific notations?
X.Y x 10Z
X.Y-Coefficient
10- Base
Z- Exponent
How do we convert a number to scientific notation?
Step 1: Move the decimal, or place a decimal, to create a number between 1 and 10. This will be the coefficient.
Step 2: Count the number of places you moved the decimal. This will be the exponent. If you moved the decimal to the right, the exponent will be negative. If you moved it to the left, the exponent will be positive.
Step 3: Write out the coefficient from step 1 multiplied by 10 raised to the exponent from step 2.
How can we convert a scientific notation to a number?
1)Move the decimal point to the right for positive exponents of 10. The exponent tells you how many places to move.
2)Move the decimal point to the left for negative exponents of 10. Again, the exponent tells you how many places to move.
What are the rules for adding, subtracting, multiplying and dividing any numbers in scientific notation?
Multiplying: Add the exponents
Divide: Subtract the exponents
Add/Subtract: Make the exponents the same, then add/subtract.
What are the steps for dimensional analysis?
1)Determine conversion factor
2)Start with what is given
3)Multiply given with conversion factor so that the units cancel out.
What are significant figures?
All know digits in a measurement plus one estimated digit.
What are the rules for counting significant figures?
Multi/divide-Answer should have the least amount of sig-fig when solved out
Add/Sub- Anser should have the least amount of sig-fig when solved.
(we count as soon as we hit the decimal, left or right)
What is precision in measurements?
How close the measurements are to each other.
How do we calculate accuracy?
Percent error (absolute value)
What is accuracy in measurements?
How close the measurements are to the actual value.
Define density
Amount of substance in a given amount os space.