Atomic Structure
Which particle has a positive charge?
Proton
What type of bond forms when electrons are transferred from one atom to another?
Ionic bond
Which phase of matter has no definite shape and volume?
Gas
Which subatomic particle determines the identity of an element?
Proton
(The number of protons determines the element’s identity)
A solution with a pH of 2 is classified as an ______.
ACIDIC
(pH 2 is strongly acidic)
Which element has 3 protons?
Lithium
What type of bond forms when two nonmetals share electrons?
Covalent Bond
What is the term for a solid changing directly into gas?
Sublimation
What is the name of the vertical columns on the Periodic Table?
Groups - Top #s / Vertical
(Vertical columns on the Periodic Table)
What ion is present in all acids?
H⁺ (hydrogen ion) (All acids release H⁺ in solution)
What is the term for atoms of the same element with different numbers of neutrons?
Isotope
Which intermolecular force is responsible for water’s high boiling point?
Hydrogen bonding
Is melting endothermic or exothermic reaction?
Endothermic (melting absorbs heat)
Which element has chemical properties most similar to fluorine?
A. Oxygen B. Chlorine C. Neon D. Sodium
Correct answer: B — Chlorine
(Elements in the same group have similar chemical properties; Cl is in Group 17 with F)
What happens to the conductivity of a solution when more ions are added?
Conductivity increases (More ions = better conductor)
Which statement describes the trend in atomic radius as you move down Group 1 on the Periodic Table?
D — Atomic radius increases and nuclear charge increases
Which compound has polar covalent bonds but is a nonpolar molecule?
A. H₂O
B. CO₂
C. NH₃
D. HCl
Correct answer: B — CO₂ (Polar bonds, but linear and symmetrical → nonpolar molecule)
Which change in matter is endothermic?
A. Water freezing
B. Water boiling
C. Steam condensing
D. Water vapor depositing
B — Water boiling (boiling requires heat input → endothermic)
As you move left to right across Period 3, which trend generally occurs?
A. Atomic radius increases B.
Electronegativity decreases
C. Metallic character decreases D.
Ionization energy decreases
Correct answer: C - Metallic character decreases
Across a period: atomic radius ↓
ionization energy ↑,
electronegativity ↑
metallic character ↓
Which solution has the highest concentration of OH⁻ ions? A. pH 2 B. pH 5 C. pH 9 D. pH 13
Correct answer: D — pH 13 (Highest pH = highest OH⁻ concentration)
A neutral atom of element X has the following electron configuration: 2–8–5 Which element is X?
A. Nitrogen
B. Fluorine
C. Phosphorus
D. Aluminum
C. Phosphorus
A student compares two liquids, X and Y.
Liquid X evaporates very quickly at room temperature.
Liquid Y evaporates slowly and has a noticeable surface tension.
Which statement best explains why Liquid Y evaporates more slowly?
A. Liquid Y has weaker intermolecular forces than Liquid X
B. Liquid Y has stronger intermolecular forces than Liquid X
C. Liquid Y has a lower molecular mass than Liquid X
D. Liquid Y contains only nonpolar molecules
ANSWER - B
Slow evaporation = stronger intermolecular forces
High surface tension = strong cohesive forces, often hydrogen bonding
Therefore, Liquid Y must have stronger IMF than Liquid X
A sample of gas is heated from 300 K to 900 K at constant pressure. According to the gas laws, the volume of the gas will:
A. decrease to one‑third B. remain the same C. triple D. increase by a factor of nine
Correct answer: C — Triple (Volume is directly proportional to temperature in Kelvin; 300 K → 900 K is ×3)
Which element is classified as a metalloid?
A. Sulfur
B. Silicon
C. Argon
D. Calcium
Correct answer: B — Silicon
(Silicon is a classic metalloid)
A student tests four household substances with pH paper. One substance turns the pH paper blue. Which conclusion is correct?
A. The substance is an acid
B. The substance has a high concentration of H⁺ ions C. The substance is a base
D. The substance has a pH less than 7
ANSWER: C (The substance is a base)
Blue pH paper indicates basic solutions
Bases have OH⁻ ions, not H⁺
Bases have pH greater than 7