Pure Substances
True/False: If a substance is considered a pure substance, it will always have the same properties
True
True/False: Mixtures are two are more substances that have been chemically combined together.
False
The ability to strike a substance without it shattering
Malleability
True/False: A physical change is always reversible.
False
What is the formula used to calculate density?
Density = mass / volume
A substance that is made of only one type of atom
Element
Type of mixture where parts of the mixture are noticeable different from one another.
Heterogeneous Mixture
Iron exposed to oxygen and forming iron oxide is an example of which chemical property?
reactivity
A phase change such as ice melting or water boiling is an example of a ______ change
A phase change such as ice melting or water boiling is an example of a PHYSICAL change
A _______ is when a solid substance forms when liquids are combined.
A PRECIPITATE is when a solid substance forms when liquids are combined.
Why is water not an element?
It contains more than one type of element
Give an example of a homogeneous mixture
Brass, Steel, Plastics, milk, lemonade, etc
Flammability is the ability to burn in the presence of ______.
Oxygen
Name 3 clues that a chemical change has occurred.
Change in color
Production of Gas
Formation of a Precipitate
Production of Heat/Light
Change in Odor
Which property of matter measures the ability to cut/scratch another substance
Hardness
Which of the following is NOT true about compounds.
a. made up of 2 or more simpler substances chemically combined.
b. share the same properties as the substances they are made of.
c. always joined in a fixed proportion.
b. share the same properties as the substances they are made of.
This is a type of liquid mixture where particles in the mixture are too large to stay evenly distributed in the liquid. This causes the mixture to separate into layers over time.
Suspension
Distillation is the process of separating a mixture based on differences in ________________.
Distillation is the process of separating a mixture based on differences in BOILING POINT.
Is shaking a soda to make it fizz is a physical change or chemical change? Explain why.
It is a physical change because the fizzing is a result of CO2 gas rapidly escaping. The CO2 gas was already present in the can
Name an example of a substance with high viscosity and a substance with low viscosity.
Label which is which in your answer.
high viscosity = syrup, honey, molasses
low viscosity = water, juice, rubbing alcohol
What is the criteria for a material to be considered a pure substance?
Matter is considered a pure substance if it always has the exact same COMPOSITION.
Mixtures and compounds are both substances that are made up of "two or more other substances"
What makes a mixture different than a compound?
The composition of a mixture can vary.
When trying to identify an unknown substance, why is it important to consider both the physical and chemical properties of the substance?
Vice Versa is true
Explain what makes a physical change and chemical change different.
The composition of a substance will remain the same during a physical change
The composition of a substance changes during a chemical change, making one or more new substances
How does the concept of density help to predict if an object will sink or float when placed in a liquid.
If the object's density is less than the density of the liquid, it will float.
If the object's density is more than the density of the liquid, it will sink.