TEAS 7 Science Practice Questions: Chemical Reactions & Equations

🧠 TEAS Memory Tricks to Remember on Test Day

OIL RIG

Oxidation Is Loss (of electrons)

Reduction Is Gain (of electrons)

C-D-D-D Rule for Reaction Types

Combination = Come together

Decomposition = Divide apart

Displacement = One element Ditches another

Double Displacement = Two compounds Double swap

Signs of a Chemical Reaction

Remember: "COGS-P"

Color change

Odor change (sometimes)

Gas produced

State change

Precipitate formed

Which statement best describes a chemical reaction?

A. A substance changes only its physical appearance

B. New substances are formed with different properties

C. Matter disappears completely

D. Energy is always absorbed

B. New substances are formed with different properties

Test Tip

If new substances form, it is a chemical change.

In the equation:

2H2+O2→2H2O2H2+O2→2H2O

The substances on the left side are called:

A. Products

B. Compounds

C. Reactants

D. Catalysts

C. Reactants

Memory Trick

Reactants React → Products Produced

Left = Reactants Right = Products

Which observation indicates a chemical reaction has occurred?

A. Ice melting

B. Water boiling

C. Gas bubbles forming

D. Cutting paper

C. Gas bubbles forming

TEAS Shortcut

Gas production = Chemical reaction

Burning magnesium ribbon produces:

A. Magnesium chloride

B. Magnesium sulfate

C. Magnesium oxide

D. Magnesium nitrate

C. Magnesium oxide

Memory Trick

Think:

Magnesium + Oxygen = Magnesium Oxide

Mg + O = MgO

When magnesium burns, what is observed?

A. Blue flame

B. Bright white flame

C. Green flame

D. No light produced

B. Bright white flame

TEAS Recall

Magnesium = Bright White Light

This question appears frequently in nursing entrance exams.

What type of reaction is shown?

2Mg+O2→2MgO2Mg+O2→2MgO

A. Decomposition

B. Double displacement

C. Combination

D. Neutralization

C. Combination

Memory Trick

Two substances become one product.

Combine = Combination

A decomposition reaction occurs when:

A. Two compounds swap ions

B. One compound breaks into simpler substances

C. An acid reacts with a base

D. Two elements combine

B. One compound breaks into simpler substances

Memory Trick

Decomposition = Decompose = Break Apart

Which reaction is a decomposition reaction?

A. H₂ + Cl₂ → 2HCl

B. 2H₂O → 2H₂ + O₂

C. Mg + O₂ → MgO

D. Na + Cl → NaCl

B. 2H₂O → 2H₂ + O₂

Quick Test Strategy

One reactant → Multiple products = Decomposition

Photosynthesis is an example of:

A. Exothermic reaction

B. Endothermic reaction

C. Combustion reaction

D. Neutralization reaction

B. Endothermic reaction

Memory Trick

Plants need sunlight energy.

If energy goes IN → Endothermic

Which reaction absorbs heat energy?

A. Exothermic reaction

B. Endothermic reaction

C. Combustion reaction

D. Oxidation reaction

B. Endothermic reaction

Memory Trick

ENDO = Energy Goes IN

An exothermic reaction:

A. Absorbs heat

B. Releases heat

C. Stops energy transfer

D. Requires sunlight

B. Releases heat

Memory Trick

EXO = Exit

Heat exits the reaction.

A precipitate is:

A. A gas produced during a reaction

B. A dissolved substance

C. An insoluble solid formed during a reaction

D. A catalyst

C. An insoluble solid formed during a reaction

Memory Trick

Think "Precipitation"

Rain falls out of clouds.

A precipitate "falls out" of solution.

Which is NOT evidence of a chemical reaction?

A. Gas production

B. Temperature change

C. Color change

D. Cutting aluminum foil

D. Cutting aluminum foil

TEAS Test Alert

Physical changes do NOT create new substances.

Which type of reaction involves one element replacing another?

A. Combination

B. Decomposition

C. Displacement

D. Double displacement

C. Displacement

Memory Trick

Displacement = Replace

One element "takes someone's place."

Double displacement reactions involve:

A. One reactant only

B. Breaking apart compounds

C. Exchange of ions between compounds

D. Burning oxygen

C. Exchange of ions between compounds

Memory Trick

Double Displacement = Double Swap

AB + CD → AD + CB

TEAS High-Yield Facts

Must Memorize

✅ Reactants = Left side

✅ Products = Right side

✅ Combination = Many → One

✅ Decomposition = One → Many

✅ Endothermic = Absorbs energy

✅ Exothermic = Releases energy

✅ Magnesium burns with a bright white flame

✅ Magnesium + Oxygen → Magnesium Oxide

✅ Photosynthesis is Endothermic

✅ Precipitate = Insoluble solid

5-Second TEAS Review Sheet

Reaction Type —> Easy Memory Trick

Combination —> Join Together

Decomposition—> Break Apart

Displacement —> Replace

Double Displacement —> Double Swap

Endothermic —> Energy IN

Exothermic —> Energy OUT

Reactants —> Left Side

Products —> Right Side

OIL RIG —> Oxidation Loss, Reduction Gain