Studied by 7 people
Qualitative observations
Based on your senses and observations
quantitative observation
Involves numbers and measurements
All parts of a lab write-up (in order)
Title, purpose, procedure, data and observations, calculations, conclusion and questions
Intensive properties
do not depend on the amount of matter present
Extensive properties
depend on the amount of matter that is present
Physical vs. chemical change
Physical - does not create a new substance, atoms are not rearranged into different compounds; Chemical - converts one substance into another; atoms are rearranged
compounds
2 or more different elements chemically combined; composition always remains the same
elements
A molecule composed of one kind of atom; cannot be broken into simpler units by chemical reactions.
homogeneous material
an item that consists of only one material throughout or a combination of multiple materials that cannot be mechanically disjointed, excluding surface coatings
heterogeneous material
a material with a composition that varies from one point to the next within its structure
mixtures
A combination of two or more substances that are not chemically combined and have varying composition (wood, soda, coffee, air)
molecules
Groups of two or more atoms held together by chemical bonds
Difference in melting points for pure substances vs mixtures
Pure substances have definite melting points; mixtures do not
Methods of separating mixtures
filtration, distillation, crystallization, chromatography, magnet, sorting by color, centrifuging
Characteristic of solids and the atoms/molecules within them
Have definite shape and volume, atoms are tightly packed and vibrate in place, strong force of attraction between particles
Characteristic of liquids and the atoms/molecules within them
definite volume but no definite shape, flow, looser attractive forces
Characteristic of gases and the atoms/molecules within them
no definite volume or shape, weak attractive forces, flow
Physical property
Characteristic that can change without turning it into a different substance (odor, volume, state, density, melting point, boiling point)
Chemical property
Characteristic that describes the ability of a substance to change to a different substance
Physical change
change that does not affect a substance's composition
chemical change
substance becomes another substance (wood burning, rusting of steel, digestion of food, growth of plants)
Alloy
mixture of a metal
pure substances
always have the same composition (elements or compounds)
Matter
Must have mass and volume
Mass vs. weight
Mass is a measurement of the amount of matter something contains (makeup stays the same everywhere), while weight is the measurement of the pull of gravity on an object (changes on different planets).
Colloids
heterogeneous, shows Tyndall effect, will not settle out over time, think snickers bar or tapioca pudding
Suspensions
heterogeneous, shows Tyndall effect, settles out over time
Solutions
Homogeneous, no definite formula, type of mixture
Scientific method
Observations 2. Formulate hypothesis 3. Experiment -- Theory, prediction, experiment repeat enough and could end up with a law
Relationship between temperature and pressure
As temperature increases, so does pressure, and as it decreases, so does pressure (because temperature increases particle movement, they move more often and therefore hit the sides of things more, increasing pressure)
Percent composition by mass
part/whole x 100
Empirical formula
Expressing the smallest whole number ratio of atoms in a compound
Molecular formula
The actual formula of a compound
What is this and what is it for?
This is a test tube, and its purpose is to hold, mix, or heat small quantities of substances
What is this and what is it for?
This is an iron ring, and its purpose is to hold up whatever is placed on the Bunsen burner
What is this and what is it for?
This is a ring stand and it holds an iron ring. Commonly, a Bunsen burner is placed beneath it to heat whatever rests on it
What is this and what is it for?
This is a test tube rack and its purpose is to hold test tubes
What is this and what is it for?
This is a Bunsen burner and its purpose is to heat things
What are these and what are they for?
These are crucible tongs and they hold the crucible
What are these and what are they for?
These are beaker tongs and they hold the beaker
What is this and what is it for?
This is a dropper pipette and its purpose is to transfer small amounts of liquid
What is this and what is it for?
This is a watch glass and is typically used for evaporation and weighing solids
What is this and what is it for?
This is a glass stirring rod and it is for stirring solutions/mixtures
What is this and what is it for?
This is a thermometer and it is for checking the temperature of something
What is this and what is it for?
This is a scoopula and it is for scooping small amounts of things and removing/scraping substances
What is this and what is it for?
This is a test tube holder and its purpose is to carry/hold test tubes
What is this and what is it for?
This is a pipestem triangle and its purpose is to hold up the crucible while it is being heated above the Bunsen burner
What is this and what is it for?
This is a crucible and cover, and its purpose is to hold, typically solids, to give them somewhere to be while they are being burned/heated over a Bunsen burner
What are these are what are they for?
These are forceps and they help hold/carry small things
What are these and what are they for?
This is a mortar and pestle and they are for grinding/crushing solids
What is this and what is it for?
This is a graduated cylinder and its purpose is to measure amounts of liquid in milliliters
What is this and what is it for?
This is an evaporating dish and it is used to allow things to heat/evaporate over time
What is this and what is it for?
This is a wire gauze and it is for protecting glassware on a Bunsen burner by diffusing the heat
What is this and what is it for?
This is a beaker and it is for measuring liquids, containing liquids/solids, and for holding things that may be used in a reaction
