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WorksheetsScience 7A Midterm Exam. Practice Quiz
Total questions: 105
Worksheet time: 53mins
Where are the reactants found in a chemical equation?
right side
after the arrow
above the arrow
left side
Which of the following indicates that a chemical change has occurred?
freezing
melting
precipitate is formed
a change in shape
In a chemical equation, new substances will be formed. What statement is false about these new substances?
Atoms are in different combinations than the reactants.
New chemical bonds have been formed.
They contain the same atoms as on the reactant side.
They are separated from the reactants by a “+” sign.
A chemical change has occurred when _____.
snow melts.
bread dough rises.
ice cubes are crushed.
coloring a picture.
In a chemical reaction, mass is conserved. What does this mean?
The type and number of atoms in the reactants equals the type and number of atoms in the products.
The mass of the products is different from the reactants.
The number of the reactants stays the same as the products during a chemical reaction.
The mass of the products is always twice the mass of the reactants.
Which statement about chemical changes is false?
may produce a change in heat or color
new substances are formed
no change in chemical properties
a chemical reaction occurs
What is the product in the chemical equation: N2 + 3 H2 → 2NH3?
H2
2 and 3
2NH3
N2, 3H2 and 2NH3
Which of the following does NOT identify that a chemical reaction has occurred?
emission of odor
change in size
gas bubble forming
bright light is produced
Which of the following changes is a physical change?
ice melting
wax burning
copper tarnishing
cake baking
Which of the following represents a chemical reaction?
precipitate
catalyst
chemical equation
atom
Which of the following describes a physical change?
A change only in the physical properties of a substance.
A change that can never be reversed.
A change when a new substance is formed.
Is the result of a chemical reaction occurring.
Which of the following is an example of a chemical change?
melting ice
burning of methane
folding a paper airplane
painting a fence
If there is more than one product in a chemical equation, the products are separated by
minus signs
plus signs
two-way arrows
equal signs
Which statement best describe the Law of Conservation of Mass?
The mass of an object on the moon is equal to the mass of that same object on Earth.
Evidence of a chemical reaction is a change in mass.
Mass can be created or destroyed.
The mass of the products is equal to the mass of the reactants.
Which statement describes a chemical reaction?
Some atoms disappear while others multiply to form the products.
New atoms are formed which combine to make the products.
The atoms of the reactants always stay together to form the products.
The atoms of the reactants rearrange and then recombine to form the products.
Which statement about energy in chemical reactions is true?
Energy is created.
Energy is not used.
Energy is destroyed.
Energy is conserved.
Cellular respiration occurs in which type of cell?
all cell except plant cells
plant cells only
both plant and animal cells
animal cells only
Complete the sentence. The products of photosynthesis are the _____.
reactants of cellular respiration.
reactants of photosynthesis.
products of cellular respiration.
products of ATP.
What type of reaction occurs when it takes more energy to break bonds in the reactants than is released when new bonds are made in the products?
endothermic
exothermic
this happens in all reactions
Which of the following is released during cellular respiration?
air
oxygen
photosynthesis
energy
When energy is absorbed in endothermic reactions it is stored in the chemical bond of products, what type of energy is this?
electricity
kinetic energy
activation energy
chemical energy
What type of reaction causes a release of heat and a rise in temperature in the surroundings?
exothermic
ectothermic
endothermic
this happens in all reactions
Which statement best describes cellular respiration?
uses glucose to make oxygen
uses ATP to make oxygen
makes glucose from carbon dioxide and water
uses glucose to make ATP
Where does photosynthesis occur in the cell?
mitochondria
nucleus
chloroplasts
cell membrane
What is the correct equation for cellular respiration?
6CO2 + 6H2O + Energy → 6O2 +C6H12O6
6O2 + C6H12O6 + Energy → 6CO2 + 6H2O
6O2 + C6H12O6 → 6CO2 + 6H2O + Energy
6CO2 + 6H2O → 6O2 + C6H12O6 + Energy
What scientific principle is demonstrated when electricity is changed to light energy?
law of conservation of electricity
law of conservation of energy
law of conservation of matter
law of conservation of mass
How are cellular respiration and photosynthesis almost opposite processes?
Photosynthesis releases energy while cellular respiration stores energy as ATP
Photosynthesis occurs in animals while cellular respiration occurs in plants
Photosynthesis captures energy from the sun while cellular respiration releases energy as ATP
Photosynthesis uses oxygen while cellular respiration produces oxygen
Which is a product of cellular respiration?
glucose (sugar)
oxygen
carbon dioxide
light
What is activation energy?
the extra energy supplied in the middle of a chemical reaction to keep it going
the energy produced in a chemical reaction
the energy needed for a chemical reaction to begin
the energy required to stop a chemical reaction
Where does cellular respiration occur in the cell?
cell membrane
mitochondria
nucleus
chloroplasts
Who stated that electrons exist in distinct circular orbits around the nucleus called energy levels?
Chadwick
Rutherford
Thomson
Bohr
What makes up the mass of the atom?
neutrons and electrons
protons and neutrons
electrons and protons
electron cloud
How many hydrogen atoms are in the compound, H2SO4?
3
1
4
2
Which statement is true about carbon dioxide (CO2) and carbon monoxide (CO)?
Both compounds are harmless gases.
Both compounds consist of the elements carbon and oxygen.
Both compounds have all the same properties.
Both compounds combine in the same ratio.
Which subatomic particle determines the identity of an element?
neutron
electron
proton
nucleus
If the atomic number of an element is 10, how many protons are there?
10
4
20
5
Chlorine has atomic number 17 and mass number 35. How many protons, electron, and neutrons are in a chlorine atom?
18 protons, 18 electrons, and 17 neutron
35 protons, 35 electrons, and 17 neutrons
17 protons, 17 electrons, and 18 neutrons
18 protons, 18 electrons, and 18 neutrons
Which analogy best describes atoms in Dalton’s atomic model?
planetary orbits
plum pudding
a solid bowling ball
blades of a fan
What particles are in the nucleus of an atom?
protons and electrons
electrons and neutrons
neutrons and protons
only protons
Which scientist stated that matter is made of atoms that cannot be created or divided and that atoms combine in specific proportions?
Bohr
Dalton
Rutherford
Thomson
How many neutrons are in an atom that has 7 electrons and a mass number of 13?
13
7
20
6
Who worked with Rutherford to discover neutrons?
Aristotle
Thomson
Chadwick
Bohr
Which part of Dalton’s Atomic Theory is NO longer supported by the modern atomic model?
All substances are made of atoms.
Atoms combine to form compounds.
All atoms of the same element are alike and have the same mass.
Atoms are the smallest particles of matter.
Which subatomic particle has a negative charge?
nucleus
neutron
proton
electron
Who discovered that the atom’s mass and positive charge are concentrated in a small area in it’s center?
Aristotle
Rutherford
Dalton
Democritus
Which is the smallest piece of an element that still represents that element?
a molecule
an electron
a quark
an atom
Who is the English scientist who concluded that atoms have negatively charged particles called electrons embedded in a solid positively charged sphere?
Bohr
Chadwick
Thomson
Rutherford
Who was the Greek philosopher who thought that matter is made up of fire, water, air, and earth?
Aristotle
Thomson
Rutherford
Democritus
Who was the Greek philosopher who said all matter is made of small particles that could not be divided?
Dalton
Aristotle
Rutherford
Democritus
Which subatomic particle has the least amount of mass?
nucleus
proton
electron
neutron
Elizabeth wanted to see how long an ice cube would float in different temperatures of water. What is is the dependent variable in Elizabeth’s experiment?
length of time ice cube floats
size of ice cube
temperature of water
amount of water
A student did an experiment to test the hypothesis that salt water freezes at a lower temperature than pure water. What is the independent variable in this experiment?
amount of water
temperature of water
salt content of water
freezing point of water
What is the factor in an experiment that is being changed?
control
dependent variable
hypothesis
independent variable
What is considered the foundation of the scientific method?
asking questions
solving problems
making observations
communicating results
What is a scientist doing when they share their findings with other scientists?
theorizing
hypothesizing
experimenting
communicating
Which best describes a possible answer to a question or solution to a problem?
reasoning
claim
evidence
explanation
What term describes a testable explanation for a question or problem?
observation
theory
hypothesis
law
What should you do if the results of an experiment turn out differently from what you expected?
determine you didn't follow the scientific method
you need to redo your experiment until you get the expected result
you should explore the possible reasons for this when you analyze your results
assume the experiment was a failure
Which statement best applies to a scientific law?
includes Einstein's theory of relativity
answers a “why” question
describes what will happen sometimes in the natural world
answers a “how” questions
What type of data is based only on your senses such as what you see, hear, or touch?
control
variable
quantitative
qualitative
Which statement best defines science?
Learning based on evidence, reasoning and repeated testing.
Learning based on politics and social science readings.
Learning based on mathematicians use of numbers to describe phenomena.
Learning based on the works of scientists in the 1800’s.
What is the difference between a collection and a system?
The parts in a system act independently.
The parts in a system interact like the parts in the collection.
The parts in a collection interact.
The parts in a system work together.
In an experiment, what is the variable that is unchanged and used to rule out other variables that may influence the results?
control
dependent variable
hypothesis
independent variable
Which of the following is NOT a part of the scientific method?
conclusion/Data Analysis
guessing
observation
experiment
Which of the following is NOT an example of a model?
question
mathematical representations
drawings
diagrams
Who developed the first periodic table of elements?
Democritus
Aristotle
Mendeleev
Use the periodic table to determine the number of neutrons in Beryllium.
9
5
13
4
Which best describes the three general groups of elements?
solid, liquid, and gas
metals, metalloids, and synthetics
metals, nonmetals, and noble gases
metals, metalloids, and nonmetals
Which element has a completely filled outer energy level?
lithium
fluorine
neon
boron
Use your periodic table to determine the number of electrons in Silicon.
28
14
7
42
Fluorine has 7 electrons in its outer level. What does this mean?
It can easily lose 7 electrons.
Fluorine is stable and non-reactive.
Fluorine wants to have a total of 4 electrons in its outer level.
It is reactive because it can easily gain one electron.
Which elements are found on the far right side of the periodic table?
metals
semiconductors
nonmetals
metalloids
Which of the following could be the chemical symbol of an element?
si
iS
Si
SI
What characteristic of the table of elements gives the ‘periodic table’ its name?
the atomic masses
the height of the columns
the families order
the repeating properties in the rows
Which of the following describe elements in group 1?
Group 1 elements are nonreactive.
Group 1 elements are known as alkali metals.
Elements in group 1 have seven valence electrons.
Magnesium and calcium are examples.
Our modern periodic table arranges the elements based on
increasing atomic mass
the number of neutronsthe number of electrons
the number of electrons
increasing atomic number
An element, like lithium has almost an empty outer electron level. This means that lithium
is brittle
will be very reactive
wants to gain electrons to fill its outer level
is a semiconductor
Which of the following is a characteristic of nonmetals?
malleable
mostly solids
shiny
poor conductors of electricity
number of protons in an atom
atomic mass
atomic number
row of the periodic table
period (horizontal - )
column (vertical I )
table based on the atomic number of elements
modern (new) periodic table
ancient (old) periodic table
how an element is represented in the periodic table
atomic number
chemical symbol
table based on the atomic mass of elements
Mendeleev’s periodic table
Modern Periodic Table
column of the periodic table
period
group or family
amount of matter in an atom
atomic mass
atomic number
Who stated that electrons exist in distinct circular orbits around the nucleus called energy levels?
Chadwick
Rutherford
Thomson
Bohr
What makes up the mass of the atom?
neutrons and electrons
protons and neutrons
electrons and protons
electron cloud
How many hydrogen atoms are in the compound, H2SO4?
3
1
4
2
Which statement is true about carbon dioxide (CO2) and carbon monoxide (CO)?
Both compounds are harmless gases.
Both compounds consist of the elements carbon and oxygen.
Both compounds have all the same properties.
Both compounds combine in the same ratio.
Which subatomic particle determines the identity of an element?
neutron
electron
proton
nucleus
If the atomic number of an element is 10, how many protons are there?
10
4
20
5
Chlorine has atomic number 17 and mass number 35. How many protons, electron, and neutrons are in a chlorine atom?
18 protons, 18 electrons, and 17 neutron
35 protons, 35 electrons, and 17 neutrons
17 protons, 17 electrons, and 18 neutrons
18 protons, 18 electrons, and 18 neutrons
Which analogy best describes atoms in Dalton’s atomic model?
planetary orbits
plum pudding
a solid bowling ball
blades of a fan
What particles are in the nucleus of an atom?
protons and electrons
electrons and neutrons
neutrons and protons
only protons
Which scientist stated that matter is made of atoms that cannot be created or divided and that atoms combine in specific proportions?
Bohr
Dalton
Rutherford
Thomson
How many neutrons are in an atom that has 7 electrons and a mass number of 13?
13
7
20
6
Who worked with Rutherford to discover neutrons?
Aristotle
Thomson
Chadwick
Bohr
Which part of Dalton’s Atomic Theory is NO longer supported by the modern atomic model?
All substances are made of atoms.
Atoms combine to form compounds.
All atoms of the same element are alike and have the same mass.
Atoms are the smallest particles of matter.
Which subatomic particle has a negative charge?
nucleus
neutron
proton
electron
Who discovered that the atom’s mass and positive charge are concentrated in a small area in it’s center?
Aristotle
Rutherford
Dalton
Democritus
Which is the smallest piece of an element that still represents that element?
a molecule
an electron
a quark
an atom
Who is the English scientist who concluded that atoms have negatively charged particles called electrons embedded in a solid positively charged sphere?
Bohr
Chadwick
Thomson
Rutherford
Who was the Greek philosopher who thought that matter is made up of fire, water, air, and earth?
Aristotle
Thomson
Rutherford
Democritus
Who was the Greek philosopher who said all matter is made of small particles that could not be divided?
Dalton
Aristotle
Rutherford
Democritus
Which subatomic particle has the least amount of mass?
nucleus
proton
electron
neutron
