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WorksheetsChemistry- Energy
Total questions: 35
Worksheet time: 38mins
Which distinguishes chemical changes from physical changes?
Physical changes alter the properties of the substance while chemical changes maintain the same properties
Physical changes are permanent while chemical changes are temporary
Chemical changes produce new substances while physical changes do not
Chemical changes result in a change in mass, while physical changes do not
Which statement best explains how periods on the periodic table are organized?
increasing number of neutrons from left to right
increasing atomic number from left to right
decreasing number of electrons from left to right
decreasing atomic mass number from left to right
Which is the best example of a pure substance?
Saltwater
Aluminum
Air
Sand
A scientist pours two liquids into a flask and swirls the flask to combine the liquids. The scientist then places the flask on a laboratory bench. After a few seconds the liquids separate into layers. How are the contents of the flask classified?
Element
Compound
Homogeneous mixture
Heterogeneous Mixture
Elements on the Periodic Table are arranged according to which characteristic?
density
atomic mass
melting point
atomic number
Which group on the Periodic Table is most reactive?
Group 1
Group 16
Group 17
Group 18
Why are Beryllium (Be), Magnesium (Mg), and Barium (Ba) in the same group?
They have similar melting points
They have are all in the same state of matter at room temperature
Elements in the same group will chemically react with and identical element
They have similar physical and chemical properties
Which best explains why the total mass of the
product(s) would be less than the total weight of the reactant(s) after a chemical reaction?
A physical change occurred
Atoms involved in the reaction lost mass.
Precipitates were created in the new solution.
Gases were released to the atmosphere.
How does a balanced chemical equation satisfy the Law of Conservation of Mass?
During a chemical reaction, the total amount of matter stays the same.
During a chemical reaction, matter is destroyed.
During a chemical reaction, one or more new substances are formed.
During a chemical reaction, the total number of atoms increases.
Which is the simplest form of matter?
element
mixture
solution
compound
Which element is a poor conductor of electricity, unmalleable and a non-metal?
Calcium (Ca)
Iron (Fe)
Aluminum (Al)
Chlorine (Cl)
Which element has the atomic number of 12?
Boron (B)
Lithium (Li)
magnesium (Mg)
Sodium (Na)
A scientist tests a water sample that was collected from a river. The results of the test are described below:
-The water is clear
-The water contains dissolved calcium
How should this water sample be classified?
As an element
As a compound
As a homogeneous mixture
As a heterogeneous mixture
Which two elements have the most similar properties
Lithium (Li) and Iron (Fe)
Boron (B) and Silicon (Si)
Copper (Cu) and Aluminum (Al)
Sodium (Na) and Potassium (K)
Which best describes the reactivity of metals when moving from left to right on the periodic table?
They become more reactive
The reactivity remains the same.
The reactivity decreases, then increases
They become less reactive.
A student lights the wick of a candle and the candle burns for several minutes. The student makes the following observations:
- Observation 1 :The white candle wick turns black as it burns.
-Observation 2: The solid candle wax near the flame transforms into a liquid.
Which choice best compares these two observations?
Observation 1 describes a physical change and observation 2 describes a chemical change
Each observation describes a physical change
Observation 1 describes a chemical change and observation 2 describes a physical change
Each observation describes a chemical change
Which of the following is an example of a compound?
Gold
Saltwater
Bronze
Sugar
A copper wire was cut into pieces and dropped into a test tube contained acid. Bubbles formed immediately, the liquid in the test tube turned green and the pieces of wire were no longer visible. Which most likely happened to the pieces of copper wire?
Show Answers
The copper wire was chemically changed when it was cut and placed in the acid.
The copper wire was physically changed when it was cut and placed in the acid
The copper wire was physically changed when it was cut and chemically changed when it was placed in the acid
The copper wire was chemically changed when it was cut and physically changed when it was placed in the acid
When two solutions are combined a bright red precipitate is formed. Which is true of the precipitate?
It has a mass greater than the two liquids.
It is formed as a result of a chemical reaction.
It has a higher temperature than the two solutions.
It is formed through a change in physical state of one of the solutions.
Which best explains why silver nitrate is a compound?
Silver nitrate is a colorless powder
Silver nitrate does not chemically react with water
Silver nitrate forms a colorless liquid when mixed with water
Silver nitrate forms when three elements chemically combine
Which would provide the best evidence that a chemical reaction has occurred?
boiling
phase change
gas formation
change in color
What does knowing an element’s column and group number tell you about the element?
atomic mass
reactivity
density
atomic number
Why are the noble gases such as helium (He) and neon (Ne) grouped together in the periodic table?
They are nonreactive gases
They are highly reactive metallic solids
They are dangerous gases when combined with water
They are liquid at room temperature and have high boiling points
Which best describes elements that are shiny, malleable, ductile, and good conductors of heat and electricity?
metals
nonmetals
metalloids
semiconductors
Which is true of a chemical equation?
Subscripts must be used with all products and reactants.
Energy must be included in the beginning of the reaction
Products and reactants must be balanced.
Coefficients must be used with all products and reactants
Which is a benefit of using fossil fuels?
They provide a lot of energy at a low cost
They cause pollution and smog
They are used faster than they can be replaced naturally
Drilling for fossil fuels can damage habitats.
Which is a disadvantage of burning fossil fuels?
The burning of fossil fuels causes pollution, smog and respiratory illnesses.
The burning of fossil fuels can cause cancer
The burning of fossil fuels can cause heart disease and anxiety attacks
Fossil fuels provide a lot of energy
What is one way to reduce the use of nonrenewable energy?
building additional gas powered factories
making more efficient gas powered automobiles
burning coal instead of wood in a fire place
mining for coal instead of drilling for oil
To ensure renewable energy resources government regulations require logging companies to replant trees after clear cutting a forrest. Why is clear cutting still a concern for the environment?
It destroys entire habitats
It usually kills all animal life
It can cause acid rain to form
It usually causes the extinction of most plant life
What will most likely occur if communities around the world increase the amount of wood they burn for heat?
CO2 in the atmosphere will increase
CO2 in the atmosphere will decrease
Dissolved Oxygen in the water will increase
Dissolved Oxygen in the water will decrease
A solid powder is composed of molecules containing silver (Ag), nitrogen (N), and oxygen (O). All of the molecules are identical. How is the substance classified?
element
compound
homogenous mixture
heterogenous mixture
A company discovers a coal reserve under a mountain. The uses bulldozers to remove soil and flatten the top to expose the bedrock. Then, the company uses machines to remove coal from the exposed bedrock. How will obtaining the coal affect the environment?
The removal of soil will increase the rate of erosion and the removal of coal from the mountain will decrease the volume of carbon dioxide in the atmosphere
The removal of soil will decrease the rate of erosion and the removal of coal from the mountain will decrease the volume of carbon dioxide in the atmosphere
The removal of soil will increase the rate of erosion and the flattening of the mountain will change the direction in which water flows off of the mountain.
The removal of soil will decrease the rate of erosion and the flattening of the mountain will change the direction in which water flows off of the mountain
Which best describes a method of obtaining energy that may cause changes in water temperature and harm to fish populations?
burning coal
using ethanol in cars
installing solar panels on a home
generating electricity in a hydroelectric power plant
Which would contribute to acid rain
the burning of fossil fuels
the use of hydroelectric power
the use of nuclear power
solar power
Which is a possible disadvantage of using flowing water to produce electricity?
ecosystem damage and loss of land
reduced carbon dioxide emissions
only suitable for industrial use
creates reservoir
