Physical/Chemical
True or False:
A chemical change creates a new substance while a physical change alters the form or appearance of a substance without changing its chemical composition.
True
What are the 6 steps of the scientific method in order?
1. Scientific Question
2. Hypothesis
3. Experiment
4. Analyze data
5. Conclusion
6. Revise hypothesis if needed
What is the unit for density?
g/mL
What are the two major categories Matter is classified into?
Pure Substance and Mixture
Draw and label the three states of matter.
Solid, Liquid, Gas
Yes or No: Can you get the original objects back after a chemical change?
NO
What step of the scientific method is this an example of:
"If an object has a density less than 1.0 g/mL then it will float when placed in water because it is less dense than water."
Hypothesis
The density of water is always exactly:
1 g/mL
What is the difference between an element and a compound. Provide 1 example for each.
Elements: 1 type of atom
Compounds: 2 or more types of atom
Draw the particles of this phase change:
Vaporization
Liquid to gas
Label these as either a physical or chemical change:
1. Cutting cheese into thin slices.
2. Cooking scrambled eggs.
3. Melting cheese on an egg.
4. Digesting scrambled eggs with cheese.
1. Physical
2. Chemical
3. Physical
4. Chemical
What do we call the information gathered during an experiment using our senses or tools. (2 words)
Observations and Data
Calculate the volume of a substance that is made up of 250 g and 5 g/mL?
50 mL
What is the difference between a homogenous and heterogenous mixture?
Homogenous you CANNOT see the different substances.
Heterogenous you CAN see the different substances.
What is the name of the phase change where a gas turns into a solid without going through the liquid phase.
Deposition
Label each as either a physical or chemical property:
1. Flammability
2. Density
3. Oxidation
4. Lustrous (shiny)
1. Chemical Property
2. Physical Property
3. Chemical Property
4. Physical Property
Label which statement is an observation, and which is a conclusion:
1. The object must have a density less than 1.0 g/mL since it floated in water.
2. The wood block floated when it was placed in water.
1. Conclusion
2. Observation
Calculate the density of a piece of Lithium (Li) metal that has a mass of 534 g and a volume of 1,000 cm3.
State whether it will sink or float in water.
Density = 0.534 g/cm3
Float
Label these items according to their classification (homogeneous OR heterogeneous):
1. Water and sand in a glass
2. Sugar dissolved in water
3. Chocolate chip cookie
4. Hamburger
1. Heterogenous
2. Homogenous
3. Heterogenous
4. Heterogenous
An ice cube melts into a puddle, the puddle evaporates into water vapor. Were the water molecules absorbing or releasing heat?
Absorbing
What is the chemical property and the physical property of this object:
An object has the ability to combust into flames and it is a colorless gas.
Physical Property: colorless gas
Chemical Property: ability to combust into flames
Identify the independent and dependent variables in this hypothesis:
"If I increase the hours of sunlight my tomato plant receives, then it will grow more tomatoes because plants rely on sunlight for energy.
Independent Variable: amount of sunlight
Dependent Variable: number of tomatoes grown
There is something wrong with this statement, rewrite it so it is a true statement:
"An object can be identified by its density, and its density will change depending on its size."
"An object can be identified by its density, and its density WILL NOT change depending on its size."
Classify the following types of Matter as either an Element or a Compound:
Platinum (Pt)
Mercury (Hg)
Table Salt (NaCl)
Carbon Dioxide (CO2)
Element
Element
Compound
Compound
Name two phase changes that are opposties of one another.
Freezing and Melting
Evaporation and Condensation
Sublimation and Deposition