Vocabulary
Anything that has mass and takes up space.
What is Matter?
What kind of matter is air?
Mixture; homogeneous
What is an example of a physical change?
Anything with a state, form, or shape change.
Are mass, volume, and density physical or chemical properties and why?
Physical; they can be observed and measured without changing the substance.
What is the difference between thermal energy and temperature?
Temperature is the feeling of hot or cold.
Thermal energy is the measure of the motion of particles in a substance.
A characteristic that can be observed without changing the matter.
What is a physical property?
What kind of matter is trail mix?
Mixture; heterogeneous
What is one sign of a chemical change?
New substance formed
Substance broken down
Color change
Temperature change
Bubbles/gas released
What is the density of a sample of a substance with a mass of 100g and a volume of 10cm3?
Density = Mass / Volume
D = 100g / 10cm3
D = 10 g/cm3
Is popcorn kernels becoming popcorn an example of an exothermic or endothermic reaction? Why?
A group of two or more atoms held together by chemical bonds.
What is a molecule?
What kind of matter is pure water?
Pure substance; compound
An apple being cut is an example of what kind of change?
Physical change
Archie needs to find the density of an intricately crafted crown, to see if it is pure gold. He has no trouble measuring the mass, but he doesn't know what to do next. What should he do?
Measure the displacement of the object using a graduated cylinder.
A northern right whale migrates from warm waters off Florida to cooler waters of the Bay of Fundy, Canada. In which area do you think more thermal energy would move from the whale to its environment?
Off Canada. Thermal energy moves from warmer objects to cooler objects. The whale in Canada is warmer than the water so the thermal energy would move from the whale to the water in the Bay of Fundy.
Separating liquids by boiling them.
What is distillation?
What kind of matter is Magnesium (Mg)?
Pure substance; element
If you cut an apple into slices and leave them in the open air, they will slowly turn brown. What kind of chemical change is happening?
Oxidation; substances in the apple are reacting with oxygen (air).
In most of the world, the metric system is used in everyday life and not just in science. Why would it make sense for people in the United States to use the metric system in everyday life, too?
Metric System: Grams, meters, liters
It would be easier to convert measurements and calculate numbers.
Paula finds that the temperature of a beaker of hot water drops several degrees in a few minutes. She says that there must be an exothermic reaction taking place in the water. Do you agree? Why?
It is not a reaction at all. Hot water cooling is a physical process you expect to happen and does not require a chemical reaction.
A mixture with multiple distinct parts.
What is a heterogeneous mixture?
What kind of matter is tap water?
Mixture; homogeneous
A bar of gold is melted into liquid. The liquid is then poured into a mold to make pieces of jewelry. Is the proces a chemical change or a physical change?
Physical change. The gold changed shape and state but did not become something else.
What is the mass of a sample of a substance with a volume of 120 mL and a density of 0.75 g/mL?
D = M/V
M = D x V
M = 0.75 g/mL x 120 mL
M = 90 g
In a chemical reaction, the reactants and the products must have the same amount of atoms on either side. What law explains this process?
The law of conservation of mass states that matter is not created or destroyed in any chemical or physical change.