Worksheets8th Grade Science Review
Total questions: 76
Worksheet time: 41mins
Which statement does not describe a chemical reaction?
A student mixes a clear liquid and a pink solid. The solid disappears and there is a temperature change.
A student leaves a clear liquid substance out on the counter. In the morning only a white solid remains.
A student bends a glow stick to mix materials, and it produces light.
Thermal energy is added to a liquid substance and it turns a different color and turns into a gas.
What is the difference between the substances represented by Co and CO?
They are two different ways to represent the element cobalt
One is the symbol for an element, and one is the formula for a compound.
Co represents the element cobalt, and CO represents the element copper
They represent two substances, each made up of two elements.
A student mixes a white solid and a clear liquid together. Which observations are evidence that a chemical reaction occurred?
It began to bubble and fizz
It turned orange
the solid disappears into the liquid
the mixture begins to smoke.
What was Mendeleyev's purpose for reorganizing the periodic table?
He wanted to fit all the elements on one page
He wanted to put element with similar characteristics in the same column
He wanted to order the elements from the lightest to the heaviest.
He wanted to put all the metals on one side of the table and gases on the other.
When Mendeleyev changed the layout, there were gaps where no known element fit. How did the gaps help scientists look for undiscovered elements? Pick all that apply.
The gaps showed scientists where elements could not exist.
The gaps showed scientists which new elements might be found.
The gaps predicted the characteristics of the new elements.
The gaps predicted the mass of the new elements.
What happens to particles of air when you push the plunger down on a closed syringe system?
The air particles move closer together
The air particles move farther apart
There are more air particles in the syringe
There are fewer air particles in the syringe.
What happen to the air particles inside a closed syringe system when you pull the plunger up?
The air particles move closer together
the air particles move farther apart
The air particles become smaller
The air particles become larger
A student was wondering about what is inside a helium balloon. Which of the following describes what is between the helium particles in the balloon. Choose all that apply.
space
air
matter
particles
nothing
What will happen if a sharp object creates a hole in a soccer ball?
Particles will rush into the ball until the pressure is equal inside and outside the ball
Particles inside the ball will speed up because the pressure inside the ball decreases
Particles will rush out of the ball until the pressure is equal inside and outside the ball
Particles outside the ball will speed up as the pressure increases
Which of the following ALWAYS results from a chemical reaction?
bubbles
fire or smoke
temperature change
a new substance
Which of these options does NOT describe a closed syringe system at equilibrium? Choose all that apply.
the pressure inside and outside is the same
the number of air particles inside and outside is the same
the system is open to the outside air
the air particles inside the syringe push the plunger up with the same force that the particles outside the syringe push the plunger down.
the number of particle collisions against the inside and outside of the plunger are the same.
A student put a cap on a bottle, trapping room temperature air inside. He put the bottle in the freezer for 15 minutes, then took it out and saw that the bottle looked crushed in on the sides. What caused the bottle to change shape.
some of the air particles got out of the bottle
the air particles in the bottle got closer together
the air particles settled to the bottom of the bottle
The air particles cooled and became smaller
A jeweler heats a silver strip and bends it into a bracelet. The jeweler then cools the bracelet. When the strip of silver is heated, the silver particles ____. Choose all that apply.
start moving
move farther apart
increase in number
get closer together
move faster
A jeweler heats a silver strip and bends it into a bracelet. He then cools the bracelet. What happens as the bracelet cools?
The kinetic energy of the particles ____.
increases and the particles move farther apart.
decreases and the particles move more slowly
decreases until the particles stop moving
does not change
An iron cube is put into a cup of water. The iron cube and the water are at the same temperature. Which particles have higher average kinetic energy?
the water particles
the iron particles
they both have the same
An iron cube is put into a cup of water. The iron cube and the water are at the same temperature. Describe energy transfer between the water and the iron.
energy transfers from the water to the iron
energy transfers from the iron to the water
energy transfers back and forth between the iron and the water
no energy is transferring between the iron and the water
Particle A is a fast moving particle that collides with particle B which is a slow moving particle. Which particle has more kinetic energy before the collision?
Particle A
Particle B
A and B have the same kinetic energy
Particle A is a fast moving particle that collides with particle B which is a slow moving particle. What happens to the kinetic energy when they collide?
Energy transfers to particle A
Energy transfers to particle B
Energy transfers to both particles
Particle A is a fast moving particle that collides with particle B which is a slow moving particle. Which particle has more kinetic energy after the collision?
Particle A
Particle B
They both have the same KE
A student places a warm can of fruit juice in a bucket of ice water. What happens to the particles of the juice?
the number of juice particles decreases as energy transfers to the ice water
energy flow decreases the size of the juice particles
cold energy decreases the motion of the juice particles
energy flow decreases the space between the juice particles
A student pours cold milk into a mug filled with hot chocolate. Which of the following statements is true? Check all that apply.
Energy flows from the cold milk to the hot chocolate
Energy flows from the hot chocolate to the cold milk
the kinetic energy of the milk particles increases
the kinetic energy of the hot chocolate particles increases
A baker has two identical cakes except one is hot (40°C) and the other is at room temperature (20°C). He places both cakes next to each other on the same cold plate (10°C). What happens to the energy of the cakes?
Only the hot cake transfers energy to the place
the plate transfers energy to the room temperature cake
both cakes transfer energy to the plate
neither cake transfers energy to the plate
The melting/freezing temperature of mercury is -39°C. A scientist put liquid mercury into a freezer that is kept at a constant temperature of -35°C. Will the liquid mercury freeze?
Yes because the freezer is cold enough to freeze mercury
No, because the freezer isn’t cold enough to freeze mercury.
Yes, because the particles will slow down enough for the mercury to freeze.
No, because there is not enough energy in the freezer to freeze the mercury.
A student dissolved 20 g of salt in a cup of water. She left the cup uncovered in an area where nobody could touch it. When she returned to the cup 10 days later, she found that all the water was gone, and there were crystals in the bottom of the cup. What is the best conclusion, based on her observations?
The water evaporated, and there is 20 g of salt in the cup
The water and some salt evaporated, but some salt is left in the cup.
There was a chemical reaction, and a new solid was left behind.
The water and salt separated and then the water evaporated, but there is no way to know what is left in the cup.
What happens to the particles when a substance changes from a liquid to a solid? Choose all that apply.
The particles change shape.
The particles change from soft to hard
The particles are held more strongly to one another
The kinetic energy of the particles changes.
The particles change into a new substance.
Which is true of dissolving? Check all that apply
requires two substances
requires a change in kinetic energy
is a phase change
does not require a chemical reaction
Which is true of melting? Check all that apply
requires two substances
requires a change in KE
is a phase change
does not require a chemical reaction
A student hangs a wet t-shirt on a clothesline. A few hours later, the t-shirt is dry. What happens to the water particles as the t-shirt dries?
the water particles are absorbed by the t-shirt
The water particles evaporate, forming a cloud.
The water particles disappear and no longer exist.
The water particles move faster and become part of the air
A student mixed together two substances that were at room temperature. The container quickly began to feel colder in the student’s hand. Which of the following statements is true? Check all that apply
The hand-and-container system is at equilibrium.
Cold was released from the mixture
Energy was absorbed by the mixture
Energy transferred from the student’s hand to the container
A scientist prepared a closed container for a chemical reaction. She poured two liquids into the bottle and quickly closed the bottle with the balloon stopper. The mixture bubbled and the balloon began to inflate. Explain why the balloon inflated.
New substances formed particles that are bigger than the ones before.
The scientist did not seal the system fast enough and more air got in.
A new gas was created and the gas took up more space.
The liquids reacted together and created more matter
Which of the statements about atoms are true? Check all that apply
All matter is made of atoms.
Atoms are found between the particles of matter
Living organisms are made of atoms
Air is between atoms in substances.
There is nothing between atoms in a gas.
Which of the following are examples of a chemical reaction? Check all that apply.
White sugar turns black when heated over a fire.
A substance evaporates from a bubbling pot on a hot stove.
The surface of a penny changes color after many years.
Melted butter becomes a solid when placed in the refrigerator
A spoonful of sugar disappears in a glass of water.
CaCO3 + 2 HCl CO2 + H2 O + CaCl2. How does this equation show that mass is conserved in the reaction? Choose the best answer.
The products have different atoms from the reactants.
The same number of atoms of each element is on both sides of the equation
The same elements appear on both sides of the equation
The same number of compounds appears on both sides of the equation
Does a chemical reaction take place inside a thermometer when the temperature raises?
Yes, because the liquid inside the thermometer takes up more space
Yes, because the liquid inside the thermometer became a new substance.
No, because the liquid inside the thermometer is the same substance
No, because the liquid inside the thermometer expanded
A student heated 25 mL of water from 10ºC to 20ºC. a. How much energy did she use to heat the water? Remember: cal = m x ∆T
55 cal
750 cal
250 cal
5 cal
When water boils, bubbles rise up through the water. What is in the bubbles?
energy
water particles
air particles
carbon dioxide particles
Which of the following best describes how the human body is organized from the largest to smallest structure?
DNA, chromosomes, cells
chromosomes, cells, DNA
cells, chromosomes, DNA
cells, DNA, chromosomes
If Joseph's dad has type O blood, and his mom has type A blood, what type blood could he have? Check all that apply.
Type A
Type O
Type B
Type X
What are the possible allele combinations for someone with B blood? Check all that apply
AA
BB
BO
AB
Offspring that are the result of sexual reproduction are:
never identical to the parent
sometimes identical to the parent
always identical to the parent
identical to other offspring.
A trait can be determined by:
one gene
many genes
the environment
all of the above
Egg and sperm combine during:
asexual reproduction of plants
asexual reproduction of animals
sexual reproduction of animals
reproduction of bacteria
Which of the following organisms reproduce sexually?
humans
plants
both humans and plants
none of the above
In the cells of most organisms, genetic information is contained in the:
cell wall
nucleus
organelle
all of the above
Scientists often use other organisms to study genetics. Fruit flies are sometimes chosen because:
they reproduce quickly
they cause disease
they do not have cells
they do no reproduce
Diseases that are inherited are usually:
caused by genes
caused by viruses
caused by environmental factors
all of the above
Which of the following is an example of asexual reproduction?
a fish releases sperm which unites with an egg of another fish
a worm splits in two; each half grows back into a complete worm
a gray cat is the offspring of a black cat and a white cat
flowers from two different plants are mated to produce a seed
The offspring of asexual reproduction is identical to the parent except in the case of:
a clone
a genetic mutation
fertilization
multicellular organisms
Which of the following statements is true?
only single-celled organisms can reproduce sexually
only single-celled organisms can reproduce asexually
only multicellular organisms can reproduce asexually
none of the above
Assume that a genetic trait is represented by the letter "a." Which of the following would most likely be used to represent the recessive condition?
AA
Aa
aa
none of the above
In the table, the empty square should be filled in as...
RR
Rr
rr
RRrr
In the table shown, the dominant condition of this characteristic is represented by:
RR, Rr, and rr
RR and Rr
RR and rr
Rr and rr
Among the offspring, what is the ratio of dominant to recessive for this trait?
3 : 1
1 : 3
2 : 2
1 : 2 : 1
This table is used to determine probability of traits in offspring as a result of:
asexual reproduction
sexual reproduction
both sexual and asexual reproduction
none of the above
Which of the following methods can provide information on human genetics?
breeding other organisms
studying human pedigrees
examining human DNA
all of the above
The offspring of sexual reproduction:
receives half of its genetic material from each parent
receives all of its genetic material from one parent
receives genetic material from an outside source
develops genetic material independent from any other source
DNA fingerprinting can be used to:
identify a person
diagnose a genetic disease
both a and b
none of the above
What is the most likely genotype of Jan?
EE
ee
Ee
EE or Ee
What is most likely the genotype of Jim?
EE
ee
Ee
EE or Ee
One of the first people to study patterns of heredity was:
Mary-Claire King
Charles Darwin
Gregor Mendel
Antoine
Marfan
By studying the diagram, you can conclude that the trait is:
dominant
recessive
dominant and recessive
partially dominant
Most human cells have _____ copies of each chromosome.
2
4
10
25
The offspring of asexual reproduction receives:
genetic material from one parent
genetic material from two parents
genetic material from an outside source
none of the above
Two parents are both carriers for a genetic trait/condition that is based on only one gene. This means that the offspring:
cannot have the trait/condition
will all be carriers for the trait/condition
have a 25% chance of inheriting the trait/condition
have a 50% chance of inheriting the trait/condition
Two dogs mate. One has brown spots and one has yellow spots. Their offspring have brown and yellow spots. This is an example of:
incomplete dominance
co-dominance
recessive trait
mutation
The genetic makeup of an organism
genotype
phenotype
carrier
pedigree
An organism that has two of the same alleles for a trait (example: ff)
genotype
phenotype
homozygous
heterozygous
A family has hemophilia, which is a dominant trait in their family. The allele pair Aa for hemophilia is
heterozygous
heterozygous recessive
homozygous
homozygous recessive
The observable traits or characteristics of an organism.
pedigree
genotype
phenotype
offspring
A person with a phenotype "O" blood must have the genotype
AO
BO
ABO
OO
Type AB blood is an example of
incomplete dominance
co-dominance
homozygous genes
double recessive genes
Mixed or blended results; the overall effect is an intermediate appearance
genotype
phenotype
incomplete dominance
codominance
The parent that controls the gender of the offspring is the
mother
father
both the mother and the father
neither parent
The soil can affect how tall a tree grows. This is an example of a/an
genetic factor
environmental factor
hereditary factor
dominant factor
This person does not have the condition, but can pass on an allele for it to their offspring
dominant
recessive
carrier
offspring
Process that helps humans repair worn out cells
sexual reproduction
asexual reproduction
renewal
cell completion
