WGU D425 INTRO TO CHEMISTRY OBJECTIVE ASSESSMENT EXAM 2026 | ACCURATE QUESTIONS & DETAILED ANSWERS | LATEST VERSION

WGU D425 INTRO TO CHEMISTRY OBJECTIVE
ASSESSMENT EXAM 2026 | ACCURATE
QUESTIONS & DETAILED ANSWERS | LATEST
VERSION
WGU D425 INTRO TO CHEMISTRY OBJECTIVE ASSESSMENT EXAM 2026

ACCURATE QUESTIONS & DETAILED ANSWERS | LATEST VERSION



INSTRUCTIONS: Each question has 5 options (A–E). The CORRECT ANSWER is
highlighted with , followed by the RATIONALE.



QUESTION 1 What is the atomic number of Carbon?

A) 4
B) 8

C) C) 6

D) 12

E) 14

CORRECT ANSWER: C) 6 RATIONALE: The atomic number represents the number
of protons in the nucleus. Carbon has 6 protons, giving it atomic number 6 on the
periodic table.


QUESTION 2 Which subatomic particle has a negative charge?

A) Proton

B) Neutron

C) Positron

D) Nucleus

E) Electron

CORRECT ANSWER: E) Electron RATIONALE: Electrons carry a negative charge
(−1). Protons carry a positive charge, and neutrons are electrically neutral.

,QUESTION 3 What is the chemical symbol for Gold?

A) Go

B) Gd

C) Ge

D) Au

E) Ag

CORRECT ANSWER: D) Au RATIONALE: Gold's symbol Au comes from the Latin
word "Aurum." It is a transition metal with atomic number 79.



QUESTION 4 Which of the following is a physical change?

A) Burning wood

B) Rusting iron

C) Melting ice

D) Digesting food

E) Exploding dynamite

CORRECT ANSWER: C) Melting ice RATIONALE: Melting ice is a physical change
because only the state of matter changes (solid to liquid); the chemical composition of
water (H₂O) remains the same.



QUESTION 5 What is the molecular formula of water?

A) HO

B) H₃O

C) H₂O

D) OH₂

E) H₂O₂

CORRECT ANSWER: C) H₂O RATIONALE: Water consists of two hydrogen atoms
bonded to one oxygen atom. H₂O₂ is hydrogen peroxide, a different compound entirely.

,QUESTION 6 Which of the following elements is a noble gas?

A) Chlorine

B) Nitrogen
C) Oxygen

D) Fluorine

E) Argon

CORRECT ANSWER: E) Argon RATIONALE: Argon (Ar) is in Group 18 of the
periodic table, which contains the noble gases. These elements have full valence shells
and are largely chemically inert.



QUESTION 7 What is the SI unit of temperature?

A) Celsius

B) Fahrenheit

C) Calorie

D) Kelvin

E) Joule

CORRECT ANSWER: D) Kelvin RATIONALE: The SI (International System of Units)
unit of temperature is the Kelvin (K). Absolute zero is 0 K, which equals −273.15°C.


QUESTION 8 How many electrons can the first energy level of an atom hold?

A) 8

B) 6

C) 2

D) 4
E) 18

CORRECT ANSWER: C) 2 RATIONALE: The first energy level (n=1) can hold a
maximum of 2 electrons, as described by the formula 2n², where n=1 gives 2(1)²=2.

, QUESTION 9 Which type of bond involves the sharing of electron pairs between
atoms?

A) Ionic bond

B) Covalent bond

C) Metallic bond
D) Hydrogen bond

E) Van der Waals bond

CORRECT ANSWER: B) Covalent bond RATIONALE: Covalent bonds form when
two atoms share one or more pairs of electrons. This is distinct from ionic bonds, where
electrons are transferred from one atom to another.


QUESTION 10 What does the law of conservation of mass state?

A) Energy cannot be created or destroyed

B) Pressure and volume are inversely related

C) Mass is neither created nor destroyed in a chemical reaction

D) All gases at equal volumes contain equal numbers of molecules

E) Matter exists in only three states
CORRECT ANSWER: C) Mass is neither created nor destroyed in a chemical
reaction RATIONALE: The law of conservation of mass, established by Antoine
Lavoisier, states that the total mass of reactants equals the total mass of products in
any chemical reaction.



QUESTION 11 What is the pH of a neutral solution at 25°C?

A) 0

B) 5

C) 7

D) 10