Back to Details Unit Test - Matter and Its Interactions Open in Editor

Unit Test - Matter and Its Interactions

PS.8.1 Summative Assessment

            📚 Science
                            🎓 Grade 8
                                        ⏱️ 55 minutes
                    

Learning Objectives

Model atomic structure including protons, neutrons, and electrons with correct locations, charges, and relative sizes.
Classify matter as elements, compounds, or mixtures based on particle arrangement models.
Analyze periodic table patterns (groups, periods, metals, nonmetals, metalloids) to predict element properties and reactivity.
Distinguish physical properties from chemical properties and identify examples of each.
Classify changes in matter as physical or chemical and identify evidence of chemical reactions.
Classify chemical reactions as endothermic or exothermic based on energy changes.
Explain the Law of Conservation of Mass and use balanced equations to show atoms are rearranged, not created or destroyed.
Compare open and closed systems and explain why mass may appear to change in an open system.
Apply knowledge of chemical reactions, reactants, products, and conservation of mass to the real-world process of photosynthesis.

            Progress
            6 sections
        

1
Atomic Structure

Question 1

How is matter defined in science?

Anything that produces light or sound
Only solids and liquids
Anything with mass and volume
Anything visible to the human eye

Question 2

What is the smallest particle of an element that still has the properties of that element?

Molecule
Atom
Cell
Electron

Question 3

What electrical charge does a proton carry?

Positive
Negative
No charge
It varies by element

Question 4

What electrical charge does a neutron carry?

Positive
Negative
Both positive and negative at the same time
No charge

Question 5

In which part of the atom are protons and neutrons found?

Orbiting the outer edge of the atom
In the electron cloud
In the nucleus
Outside the atom entirely

Question 6

Where are electrons located within an atom?

Inside the nucleus alongside protons
Attached directly to neutrons
Between neighboring atoms
In the space surrounding the nucleus

Question 7

What does an element's atomic number represent?

The number of protons, which identifies the element
The combined count of protons and neutrons
The total electron count only
The mass of the atom in grams

Question 8

How is the mass number of an atom calculated?

By counting protons only
By counting electrons only
By adding protons and neutrons
By weighing one electron on a precision instrument

Question 9

In a neutral atom, the number of protons is equal to the number of which other particle?

Electrons
Neutrons found in the nucleus
Molecules
Compounds

2
Classifying Matter

Question 10

What is an element?

Two or more atom types bonded together in a fixed ratio
A pure substance made of only one type of atom
A mixture separable by filtering
Any solid found in nature

Question 11

What is a compound?

A pure substance consisting of only one type of atom throughout
Two or more substances physically mixed
Another word for mixture
Two or more different atoms chemically bonded in a fixed ratio

Question 12

What best describes a mixture?

A single atom type bonded together
A substance with a fixed chemical formula
Two or more substances combined without chemical bonding
A liquid substance that can never be separated into parts

Question 13

Salt water looks the same throughout and its parts are not visible. What type of mixture is it?

Heterogeneous mixture
Compound
Element
Homogeneous mixture

Question 14

Trail mix contains visible pieces of nuts, chocolate, and dried fruit. What type of mixture is it?

Heterogeneous mixture
Homogeneous mixture with evenly distributed parts
Compound
Element

Question 15

A pure substance is always classified as one of two things. What are they?

Metal or nonmetal depending on its conductivity
Solid or liquid
Element or compound
Atom or electron

Question 16

A compound can only be broken down into its elements by what type of process?

Physical means such as filtering or evaporation
A chemical process
Using a magnet to attract individual atoms
It cannot be separated under any circumstances

3
The Periodic Table

Question 17

How are elements arranged on the periodic table?

By increasing mass number
By increasing atomic mass
By increasing number of neutrons
By increasing atomic number

Question 18

On the periodic table, what is a group (also called a family)?

A vertical column of elements with similar properties
A horizontal row across the table
A section of the table containing only the noble gases
A random assortment of metals

Question 19

On the periodic table, what is a period?

A vertical column of related elements
A horizontal row where properties change gradually across it
A diagonal line separating metals from nonmetals
The amount of time required for an element to fully decay

Question 20

On which side of the periodic table are metals generally located?

Right side only
Along the staircase line
Left and center
Bottom row only

Question 21

Which set of properties is characteristic of metals?

Brittle, dull, and poor conductors
Cannot be bent or shaped under any conditions
Poor conductors that exist as gases at room temperature
Shiny, good conductors, malleable

Question 22

On which side of the periodic table are nonmetals located?

Left side
Center
Right side
Scattered randomly throughout the entire table

Question 23

What is a metalloid?

An element found exclusively in Group 1
A metal that has been melted into liquid form
A nonmetal that conducts electricity as well as any pure metal
An element with both metal and nonmetal properties

Question 24

Which group on the periodic table contains the highly reactive alkali metals?

Group 1
Group 17
Group 18
Group 8

Question 25

What makes the noble gases in Group 18 unique among all elements?

They are extremely unreactive
They are the most reactive of all elements
They exist only as liquids at room temperature
They are the heaviest elements on the table

4
Physical and Chemical Properties and Changes

Question 26

What is a physical property of a substance?

A trait describing how the substance reacts with other substances
A trait only observable during a chemical reaction
A trait that applies exclusively to gases
A trait observable without changing the substance's identity

Question 27

Which of these is an example of a chemical property?

Density
Flammability
Boiling point
Color

Question 28

When ice melts into liquid water, what type of change has occurred?

Physical change
Chemical change
Nuclear change
No change has occurred

Question 29

Which observation provides evidence that a chemical change has taken place?

The substance shrinks in physical size but stays the same
The substance is sliced in half
The substance dissolves in water
Gas bubbles form, the color changes, or a precipitate appears

Question 30

What is a precipitate?

A solid formed when two solutions react
A starting substance in a reaction
A liquid that dissolves other substances
A substance that speeds up a reaction

Question 31

What defines an exothermic reaction?

It absorbs energy and feels cold to the touch
It does not involve any energy transfer
It releases energy as heat or light
It only takes place inside a closed container

Question 32

What defines an endothermic reaction?

It releases heat and produces light
It absorbs energy and feels cold
It creates entirely new atoms
It only occurs in the presence of metals

5
Conservation of Mass and Balanced Equations

Question 33

What does the Law of Conservation of Mass state?

Mass doubles during every chemical reaction that takes place
New mass is created whenever products form
Mass always decreases during a reaction
In a closed system, total mass stays the same

Question 34

Which scientist is credited with establishing the Law of Conservation of Mass?

Isaac Newton
Antoine Lavoisier
Albert Einstein
Dmitri Mendeleev, creator of the periodic table

Question 35

In a chemical equation, the starting substances on the left side of the arrow are called what?

Products
Precipitates
Reactants
Coefficients

Question 36

In a chemical equation, the substances that form as a result of the reaction are called what?

Products
Reactants
Elements
Mixtures

Question 37

For a chemical equation to be balanced, what must be true on both sides of the arrow?

The count of each type of atom must be equal
The temperature must be the same
The number of molecules must be identical
The physical states of all substances must match

Question 38

When balancing a chemical equation, which numbers are you allowed to change?

Subscripts
Coefficients
Atomic numbers of the elements involved
Chemical symbols

Question 39

What is a closed system?

A system that freely exchanges matter and energy with its surroundings
A system with no chemical reactions occurring inside it
A system that does not allow matter in or out
A system found exclusively in laboratory settings

Question 40

A burning log produces ash that weighs less than the original log. Why does the mass appear to decrease?

Mass was destroyed by the flames
The fire converted the matter of the log into pure energy
The ash is a different element with inherently less mass
Gases escaped into the air, so total mass is actually conserved

6
Photosynthesis as a Chemical Reaction

Question 41

Which balanced equation correctly represents the chemical reaction of photosynthesis?

$\ce{CO2 + O2 -> C6H12O6 + H2O}$
$\ce{6CO2 + 6H2O -> C6H12O6 + 6O2}$ (with sunlight)
$\ce{C6H12O6 + O2 -> CO2 + H2O}$ (cellular respiration, not photosynthesis)
$\ce{H2O + O2 -> CO2 + C6H12O6}$

Question 42

In the photosynthesis reaction, which two substances serve as the reactants?

Glucose and oxygen
Carbon dioxide and oxygen
Carbon dioxide and water
Glucose and water

Question 43

What role does sunlight play in the process of photosynthesis?

It is one of the products formed by the reaction
It provides the energy needed to drive the reaction
It replaces carbon dioxide as a reactant
It breaks glucose apart into individual oxygen molecules

Question 44

What two substances are produced as a result of photosynthesis?

Carbon dioxide and water
Oxygen and carbon dioxide
Glucose and water
Glucose and oxygen

Question 45

Why is photosynthesis considered essential for most life on Earth?

It removes all water from the atmosphere
It converts oxygen into carbon dioxide for animals to use
It produces oxygen and glucose that most organisms depend on
It destroys all harmful sunlight before it reaches the ground

Question 46

In the equation $\ce{6CO2 + 6H2O -> C6H12O6 + 6O2}$ , where do the carbon atoms in glucose originally come from?

Carbon dioxide
Oxygen gas in the air
Sunlight energy
Water

Question 47

Why is photosynthesis described as the main entry point of energy into nearly every food chain?

Plants convert sunlight into chemical energy stored in glucose
Plants absorb chemical energy directly from nearby animals
Plants create energy from nothing at all
Plants turn oxygen directly into food

Question 48

If photosynthesis suddenly stopped worldwide, what would most likely happen first?

Oxygen levels in the atmosphere would increase
The food supply for most organisms would collapse
Plants would begin to grow faster
The oceans would immediately and completely dry up

Question 49

Which type of organism performs photosynthesis and introduces chemical energy into the biosphere?

Humans
Green plants
Wolves
Fungi that decompose dead organic material

Question 50

Why is the oxygen released during photosynthesis vital for animals and humans?

It allows them to perform cellular respiration
Plants use it to manufacture carbon dioxide
It converts sunlight into heat energy for animals
It breaks down glucose inside plant cells

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