Science NLN practice questions (correct answers)
To be isotopes, two atoms of the same element must have a different
number of
(A) neutrons.
(B) protons.
(C) electrons.
(D) quarks. correct answers (A) neutrons.
Depending on its environment, a substance that can act as either an acid
or a base is described as
(A) amphoteric.
(B) an isomer.
(C) hydrolytic.
(D) a polymer. correct answers (A) amphoteric.
A certain substance is not broken down in a chemical reaction. The substance
is most likely
(A) a compound.
(B) an aqueous solution.
(C) an element.
(D) a heterogeneous mixture. correct answers (C) an element.
A hydrogen ion concentration of 1 × 10−7 M in a solution is considered
(A) basic.
(B) alkali.
(C) acidic.
(D) neutral. correct answers (D) neutral.
The radioactive isotope I-131 has a half-life of 8 days. What fraction of
a sample of I-131 will remain after 24 days?
(A) 1⁄4
(B) 1⁄16
(C) 1⁄8
(D) 1⁄2 correct answers (C) 1⁄8
Which of the following particles/rays is not a type of radioactive emanation?
(A) alpha particle
(B) beta particle
(C) gamma ray
(D) carbon-12 correct answers (D) carbon-12
The strongest acid can be found in which of the following pH ranges?
(A) 11.1−12
(B) 7.1−8.2
(C) 4.5−5.7
, (D) 1.0−2.0 correct answers (D) 1.0−2.0
The symbol K on the periodic table stands for
(A) potassium.
(B) calcium.
(C) carbon.
(D) phosphorus. correct answers (A) potassium.
Which of the following reactions releases heat energy?
(A) double replacement
(B) decomposition
(C) endothermic
(D) exothermic correct answers (D) exothermic
Which gas law states that the volume of a gas is inversely proportional
to the pressure?
(A) Ideal Gas Law
(B) Boyle's Law
(C) Combined Gas Law
(D) Charles' Law correct answers (B) Boyle's Law
What type of bond is created when bromine and magnesium are reacted
to form MgBr2?
(A) polar covalent
(B) metallic
(C) ionic
(D) nonpolar covalent correct answers (C) ionic
Which of the following wavelengths of visible light is best absorbed
by chlorophyll?
(A) 300nm
(B) 495nm
(C) 665nm
(D) 550nm correct answers (C) 665nm
The xylem vessels of a plant are responsible for carrying
(A) water up through the plant.
(B) light energy to the leaves.
(C) chlorophyll to the leaves.
(D) oxygen into the leaves. correct answers (A) water up through the plant.
When placed in distilled water, a human red blood cell
(A) shrivels up.
(B) neither shrinks nor swells.
(C) takes up more salts to balance all concentrations.
(D) swells to a larger size. correct answers (D) swells to a larger size.
To be isotopes, two atoms of the same element must have a different
number of
(A) neutrons.
(B) protons.
(C) electrons.
(D) quarks. correct answers (A) neutrons.
Depending on its environment, a substance that can act as either an acid
or a base is described as
(A) amphoteric.
(B) an isomer.
(C) hydrolytic.
(D) a polymer. correct answers (A) amphoteric.
A certain substance is not broken down in a chemical reaction. The substance
is most likely
(A) a compound.
(B) an aqueous solution.
(C) an element.
(D) a heterogeneous mixture. correct answers (C) an element.
A hydrogen ion concentration of 1 × 10−7 M in a solution is considered
(A) basic.
(B) alkali.
(C) acidic.
(D) neutral. correct answers (D) neutral.
The radioactive isotope I-131 has a half-life of 8 days. What fraction of
a sample of I-131 will remain after 24 days?
(A) 1⁄4
(B) 1⁄16
(C) 1⁄8
(D) 1⁄2 correct answers (C) 1⁄8
Which of the following particles/rays is not a type of radioactive emanation?
(A) alpha particle
(B) beta particle
(C) gamma ray
(D) carbon-12 correct answers (D) carbon-12
The strongest acid can be found in which of the following pH ranges?
(A) 11.1−12
(B) 7.1−8.2
(C) 4.5−5.7
, (D) 1.0−2.0 correct answers (D) 1.0−2.0
The symbol K on the periodic table stands for
(A) potassium.
(B) calcium.
(C) carbon.
(D) phosphorus. correct answers (A) potassium.
Which of the following reactions releases heat energy?
(A) double replacement
(B) decomposition
(C) endothermic
(D) exothermic correct answers (D) exothermic
Which gas law states that the volume of a gas is inversely proportional
to the pressure?
(A) Ideal Gas Law
(B) Boyle's Law
(C) Combined Gas Law
(D) Charles' Law correct answers (B) Boyle's Law
What type of bond is created when bromine and magnesium are reacted
to form MgBr2?
(A) polar covalent
(B) metallic
(C) ionic
(D) nonpolar covalent correct answers (C) ionic
Which of the following wavelengths of visible light is best absorbed
by chlorophyll?
(A) 300nm
(B) 495nm
(C) 665nm
(D) 550nm correct answers (C) 665nm
The xylem vessels of a plant are responsible for carrying
(A) water up through the plant.
(B) light energy to the leaves.
(C) chlorophyll to the leaves.
(D) oxygen into the leaves. correct answers (A) water up through the plant.
When placed in distilled water, a human red blood cell
(A) shrivels up.
(B) neither shrinks nor swells.
(C) takes up more salts to balance all concentrations.
(D) swells to a larger size. correct answers (D) swells to a larger size.
