PAX Science NLN Exam – Verified Questions with 100%
Accurate Answers – A+ Graded –2025/2026 Edition
This document includes verified and fully updated questions with 100% accurate answers for the
Science section of the NLN Pre-Admission Exam (PAX), tailored for the 2025/2026 edition. It
covers biology, chemistry, physics, anatomy & physiology, and scientific reasoning—all aligned
with current PAX test standards. An essential study guide for nursing and allied health applicants
aiming to boost their science scores and gain program admission.
A person blows his breath into a straw that is placed in limewater. The
limewater becomes cloudy because the person's breath contains
A.) carbon dioxide.
B.) hydrogen.
C.) oxygen.
D.) nitrogen.
answer: carbon dioxide.
A physician measures the pulse and blood pressure (BP) of all patients
on a routine basis. Which of these measurements show the normal BP
values for a resting adult patient?
A.) 125/95 mm Hg
B.) 120/80 mm Hg
C.) 100/80 mm Hg
D.) 72/120 mm Hg
answer: 120/80 mm Hg
A woman suddenly chokes on a piece of food and clutches frantically at
her throat. An immediate remedy is to
A.) have her bend forward and tell her to cough.
B.) insert a finger or a blunt object toward the back of the mouth.
C.) apply quick, hard pressures successively to her abdomen, just
beneath her diaphragm.
D.) phone "emergency" for help.
,answer: apply quick, hard pressures successively to her abdomen, just
beneath her diaphragm.
An unknown gas is more dense than air, does not support combustion,
and turns a limewater solution cloudy. This gas is most probably
A.) ammonia.
B.) methane.
C.) carbon dioxide.
C.) hydrogen.
answer: carbon dioxide.
Human testes produce
A.) eggs.
B.) follicle stimulating hormone.
C.) growth hormone.
D.) spermatozoa.
answer: spermatozoa.
If a red light is passed through a dilute solution of chlorophyll solution,
the spectrophotometer will detect what amount of transmittance of this
light?
A.) 100%
B.) 50 - 75%
C.) Less than 25%
D.) None
answer: 50 - 75%
In diagnostic testing, the electroencephalogram permits the physician to
A.) examine the impulses of the specialized muscle cells of the heart.
B.) examine the impulses of the nerve cells within the brain.
C.) measure the pressure within the eye.
D.) measure the amount of air upon exhalation.
answer: examine the impulses of the nerve cells within the brain.
To sterilize a metal probe in the office, a dentist could use a steam
sterilizer. If unavailable, the next most effective method to sterilize the
instrument would be
A.) boiling it in water for 15 minutes.
B.) dipping it into a concentrated acid solution.
C.) heating it in a hot air oven at 160°C for 20 minutes.
,D.) washing it in soap and water.
answer: boiling it in water for 15 minutes.
In varieties of matter, the term heterogeneous may be applied to
A.) elements, but not compounds.
B.) compounds, but not elements.
C.) compounds and elements, but not mixtures.
D.) mixtures, but not elements or compounds.
answer: mixtures, but not elements or compounds.
Heat energy is absorbed in which of these phase changes?
A.) Br2 (l) -> Br2(s)
B.) Br2 (g) --> Br2(l)
C.) Br2 (l) -> Br2(g)
D.) Br2 (g) -> Br2(s)
answer: Br2 (l) -> Br2(g)
Periodontitis is an inflammatory condition of the
A.) gum tissue that surrounds the neck of each tooth.
B.) pulp that contains nerve cells and blood vessels of the tooth.
C.) dentin that surrounds the soft part of a tooth.
D.) enamel that provides a hard surface for chewing.
answer: gum tissue that surrounds the neck of each tooth.
When three resistors of 10.0 ohms each are placed in series, the total
resistance is
A.) 3.3 ohms.
B.) 10.0 ohms.
C.) 30.0 ohms.
D.) 40.6 ohms.
30.0 ohms
When your muscles atrophy, they
A.) waste away.
B.) stiffen up.
C.) become fatigued.
D.) gain strength.
answer: Waste away
Which of these could be stopped by a sheet of paper?
, A.) Alpha particle.
B.) Beta particle.
C.) Gamma ray.
D.) Cosmic ray.
answer: Alpha particle
Which of these is NOT an organic compound?
A.) CH4 (methane).
B.) C6H12O6 (glucose).
C.) CH3COOH (acetic acid).
D.) HCl (hydrochloric acid).
answer: HCl (hydrochloric acid).
Which of these is the correct sequence of chambers through which blood
flows in the human heart and lungs?
A.) Right ventricle; right atrium; lungs; left atrium; left ventricle.
B.) Right atrium; right ventricle; lungs; left atrium; left ventricle.
C.) Left ventricle; left atrium; lungs; right atrium; right ventricle.
D.) Left atrium; left ventricle; lungs; right atrium; right ventricle.
answer: Right atrium; right ventricle; lungs; left atrium; left ventricle.
Which of these processes is used to free contaminated water of bacteria?
A.) Filtering.
B.) Passing it through charcoal.
C.) Treating it with chlorine.
D.) Allowing it to settle.
answer: Treating it with chlorine
Which of these structures contains valves to prevent blood from flowing
in the wrong direction?
A.) Veins.
B.) Arteries.
C.) Capillaries.
D.) Lymph ducts.
answer: Veins
Which of these structures of the male reproductive system carries sperm
cells from the testes to the lower part of the abdomen?
A.) Urethra.
Accurate Answers – A+ Graded –2025/2026 Edition
This document includes verified and fully updated questions with 100% accurate answers for the
Science section of the NLN Pre-Admission Exam (PAX), tailored for the 2025/2026 edition. It
covers biology, chemistry, physics, anatomy & physiology, and scientific reasoning—all aligned
with current PAX test standards. An essential study guide for nursing and allied health applicants
aiming to boost their science scores and gain program admission.
A person blows his breath into a straw that is placed in limewater. The
limewater becomes cloudy because the person's breath contains
A.) carbon dioxide.
B.) hydrogen.
C.) oxygen.
D.) nitrogen.
answer: carbon dioxide.
A physician measures the pulse and blood pressure (BP) of all patients
on a routine basis. Which of these measurements show the normal BP
values for a resting adult patient?
A.) 125/95 mm Hg
B.) 120/80 mm Hg
C.) 100/80 mm Hg
D.) 72/120 mm Hg
answer: 120/80 mm Hg
A woman suddenly chokes on a piece of food and clutches frantically at
her throat. An immediate remedy is to
A.) have her bend forward and tell her to cough.
B.) insert a finger or a blunt object toward the back of the mouth.
C.) apply quick, hard pressures successively to her abdomen, just
beneath her diaphragm.
D.) phone "emergency" for help.
,answer: apply quick, hard pressures successively to her abdomen, just
beneath her diaphragm.
An unknown gas is more dense than air, does not support combustion,
and turns a limewater solution cloudy. This gas is most probably
A.) ammonia.
B.) methane.
C.) carbon dioxide.
C.) hydrogen.
answer: carbon dioxide.
Human testes produce
A.) eggs.
B.) follicle stimulating hormone.
C.) growth hormone.
D.) spermatozoa.
answer: spermatozoa.
If a red light is passed through a dilute solution of chlorophyll solution,
the spectrophotometer will detect what amount of transmittance of this
light?
A.) 100%
B.) 50 - 75%
C.) Less than 25%
D.) None
answer: 50 - 75%
In diagnostic testing, the electroencephalogram permits the physician to
A.) examine the impulses of the specialized muscle cells of the heart.
B.) examine the impulses of the nerve cells within the brain.
C.) measure the pressure within the eye.
D.) measure the amount of air upon exhalation.
answer: examine the impulses of the nerve cells within the brain.
To sterilize a metal probe in the office, a dentist could use a steam
sterilizer. If unavailable, the next most effective method to sterilize the
instrument would be
A.) boiling it in water for 15 minutes.
B.) dipping it into a concentrated acid solution.
C.) heating it in a hot air oven at 160°C for 20 minutes.
,D.) washing it in soap and water.
answer: boiling it in water for 15 minutes.
In varieties of matter, the term heterogeneous may be applied to
A.) elements, but not compounds.
B.) compounds, but not elements.
C.) compounds and elements, but not mixtures.
D.) mixtures, but not elements or compounds.
answer: mixtures, but not elements or compounds.
Heat energy is absorbed in which of these phase changes?
A.) Br2 (l) -> Br2(s)
B.) Br2 (g) --> Br2(l)
C.) Br2 (l) -> Br2(g)
D.) Br2 (g) -> Br2(s)
answer: Br2 (l) -> Br2(g)
Periodontitis is an inflammatory condition of the
A.) gum tissue that surrounds the neck of each tooth.
B.) pulp that contains nerve cells and blood vessels of the tooth.
C.) dentin that surrounds the soft part of a tooth.
D.) enamel that provides a hard surface for chewing.
answer: gum tissue that surrounds the neck of each tooth.
When three resistors of 10.0 ohms each are placed in series, the total
resistance is
A.) 3.3 ohms.
B.) 10.0 ohms.
C.) 30.0 ohms.
D.) 40.6 ohms.
30.0 ohms
When your muscles atrophy, they
A.) waste away.
B.) stiffen up.
C.) become fatigued.
D.) gain strength.
answer: Waste away
Which of these could be stopped by a sheet of paper?
, A.) Alpha particle.
B.) Beta particle.
C.) Gamma ray.
D.) Cosmic ray.
answer: Alpha particle
Which of these is NOT an organic compound?
A.) CH4 (methane).
B.) C6H12O6 (glucose).
C.) CH3COOH (acetic acid).
D.) HCl (hydrochloric acid).
answer: HCl (hydrochloric acid).
Which of these is the correct sequence of chambers through which blood
flows in the human heart and lungs?
A.) Right ventricle; right atrium; lungs; left atrium; left ventricle.
B.) Right atrium; right ventricle; lungs; left atrium; left ventricle.
C.) Left ventricle; left atrium; lungs; right atrium; right ventricle.
D.) Left atrium; left ventricle; lungs; right atrium; right ventricle.
answer: Right atrium; right ventricle; lungs; left atrium; left ventricle.
Which of these processes is used to free contaminated water of bacteria?
A.) Filtering.
B.) Passing it through charcoal.
C.) Treating it with chlorine.
D.) Allowing it to settle.
answer: Treating it with chlorine
Which of these structures contains valves to prevent blood from flowing
in the wrong direction?
A.) Veins.
B.) Arteries.
C.) Capillaries.
D.) Lymph ducts.
answer: Veins
Which of these structures of the male reproductive system carries sperm
cells from the testes to the lower part of the abdomen?
A.) Urethra.
