NEX Basic Chemistry: Atomic Structure and Chemical Reactions 3

Question 1

Which of the following best describes an exothermic reaction?

Accepted Answer

Releases heat to the surroundings

Answer

An exothermic reaction releases energy in the form of heat to its surroundings, resulting in a net decrease in the energy of the system.

Question 2

What type of bond holds sodium and chloride together in table salt (NaCl)?

Accepted Answer

Ionic bond

Answer

Sodium chloride is held together by ionic bonds, formed when sodium transfers an electron to chlorine, creating oppositely charged ions that attract each other.

Question 3

Which subatomic particle has no electrical charge?

Accepted Answer

Neutron

Answer

Neutrons are electrically neutral particles found in the nucleus alongside protons. They contribute to atomic mass but carry no charge.

Question 4

In a balanced chemical equation, what must be equal on both sides?

Accepted Answer

Number of atoms of each element

Answer

According to the Law of Conservation of Mass, the number of atoms of each element must be equal on both sides of a balanced chemical equation.

Question 5

What is an isotope?

Accepted Answer

An atom with a different number of neutrons

Answer

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons, resulting in different atomic masses.

(NEX) Nursing Entrance Exam Practice Test

(NEX) Nursing Entrance Exam Practice Test

NEX Basic Chemistry: Atomic Structure and Chemical Reactions 3