Matter that is uniform and unchanging is called a ________.
pure substance (substance)
A _________ ___________ is a characteristic that can be observed or measured without changing the sample's composition.
physical property
Cutting the paper into pieces, crumpling the paper into a ball, etc....
mixture
State the Law of Conservation of Mass.
Mass of reactants = mass of products
This state of matter has no definite shape and no definite volume
gas
Give one chemical property of milk
curdles with Diet Coke, dehydrated creamer is flammable
You have a piece of paper. Give a chemical change that can occur.
Burn the paper in a fire, bleaching the paper white
Steel is an example of an ________ --a homogeneous mixture or solution of iron and carbon.
alloy
Explain how to find the percent by mass.
Take the mass of the element and divide by the mass of the compound. Multiply by 100 to make it a percent.
Homogeneous mixtures are also called __________
solutions
Give an example of a physical property of milk
It is white, a liquid at room temperature, there is little smell
What are two signs a chemical reaction has occurred?
How can you recognize if something is an element if you are unsure, but given the name?
Look for it on the periodic table.
A 28.0 gram sample of nitrogen gas combines completely with 6.0 grams of hydrogen gas to form ammonia. What is the mass of ammonia formed? Write out the equation to illustrate your answer.
Nitrogen gas + hydrogen gas ------> ammonia
(28.0) + (6.0) (34.0)
In a reaction, _____________ form ____________.
Copper forms a deep blue solution when in contact with ammonia. Is this a physical or chemical property? Explain.
It is a chemical property because copper is changing into another substance with new properties.
Describe the result of a physical change.
A substance does not change it's composition (what it's made up of), but changes it's appearance. Examples melting, bending, tearing.
___________ is a way to separate mixtures based on differences in boiling points.
Distillation
What is the percent by mass of bromine in MgBr2?
86.8%
We have 118 known ________ and they are organized in the _________ _________.
elements, periodic table
Changing states (liquid water into ice) is an example of a ________ property. Why?
Physical--The substance is just changing form and can be changed back to the original substance by adding/removing energy. It's composition is not changed.
If I pour 100 mL of water from a water bottle, into a beaker, does its volume change? (Does it take up more or less space?)
It's volume does not change. 100 mL may look different depending of the shape/size of the container, but it will still be 100 mL when measured.
Hydrogen is a gas and oxygen is a gas, but when they are combined together chemically, they can produce a liquid. Explain how this is possible.
If a chemical change occurs, the product will have different properties than the reactants that make it up.
If given 6.0 grams of water, how many grams of oxygen could you collect if you could separate it from hydrogen?
5.3 grams of oxygen