Science NLN practice questions with
complete solutions16
The reaction 2NaI + Cl2→ 2NaCl + I2 demonstrates a
(A) decomposition reaction.
(B) synthesis reaction.
(C) single replacement reaction.
(D) double replacement reaction. - ANSWERS-(C) single replacement reaction.
An electromagnet is holding a 1,500-kg car at a height of 25 m above
the ground. The magnet then experiences a power outage, and the car
falls to the ground (without injuring anyone). Which of the following
is false?
(A) The car had a potential energy of 367.5 kJ.
(B) 367.5 kJ of potential energy is converted to kinetic energy.
(C) The car still has a potential energy of 367.5 kJ when it hits the ground.
(D) The potential energy is converted to kinetic energy and then converted
to sound energy. - ANSWERS-(C) The car still has a potential energy of 367.5 kJ when it hits the
ground.
To be isotopes, two atoms of the same element must have a different
number of
(A) neutrons.
(B) protons.
(C) electrons.
,(D) quarks. - 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. - 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. - 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. - 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 - 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 - 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 - ANSWERS-(D) 1.0−2.0
The symbol K on the periodic table stands for
(A) potassium.
(B) calcium.
(C) carbon.
(D) phosphorus. - ANSWERS-(A) potassium.
Which of the following reactions releases heat energy?
(A) double replacement
(B) decomposition
(C) endothermic
(D) exothermic - ANSWERS-(D) exothermic
complete solutions16
The reaction 2NaI + Cl2→ 2NaCl + I2 demonstrates a
(A) decomposition reaction.
(B) synthesis reaction.
(C) single replacement reaction.
(D) double replacement reaction. - ANSWERS-(C) single replacement reaction.
An electromagnet is holding a 1,500-kg car at a height of 25 m above
the ground. The magnet then experiences a power outage, and the car
falls to the ground (without injuring anyone). Which of the following
is false?
(A) The car had a potential energy of 367.5 kJ.
(B) 367.5 kJ of potential energy is converted to kinetic energy.
(C) The car still has a potential energy of 367.5 kJ when it hits the ground.
(D) The potential energy is converted to kinetic energy and then converted
to sound energy. - ANSWERS-(C) The car still has a potential energy of 367.5 kJ when it hits the
ground.
To be isotopes, two atoms of the same element must have a different
number of
(A) neutrons.
(B) protons.
(C) electrons.
,(D) quarks. - 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. - 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. - 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. - 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 - 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 - 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 - ANSWERS-(D) 1.0−2.0
The symbol K on the periodic table stands for
(A) potassium.
(B) calcium.
(C) carbon.
(D) phosphorus. - ANSWERS-(A) potassium.
Which of the following reactions releases heat energy?
(A) double replacement
(B) decomposition
(C) endothermic
(D) exothermic - ANSWERS-(D) exothermic
