Question 1: What is the smallest unit of an element that retains its chemical properties? A) Molecule B) Atom C) Compound D) Isotope

Explanation: The correct answer is B) Atom. An atom is the smallest unit of an element that retains its chemical properties and consists of a nucleus (protons and neutrons) surrounded by electrons.

Question 2: Which subatomic particle has a negative charge? A) Proton B) Neutron C) Electron D) Positron

Explanation: The correct answer is C) Electron. Electrons are subatomic particles with a negative charge and are found in energy levels around the nucleus of an atom.

Question 3: What is the process by which a solid changes directly into a gas without passing through the liquid phase? A) Condensation B) Evaporation C) Sublimation D) Freezing

Explanation: The correct answer is C) Sublimation. Sublimation is the process in which a solid changes directly into a gas without becoming a liquid first.

Question 4: Which type of bond involves the sharing of electron pairs between atoms? A) Ionic Bond B) Covalent Bond C) Metallic Bond D) Hydrogen Bond

Explanation: The correct answer is B) Covalent Bond. A covalent bond is formed when atoms share electron pairs, typically between nonmetal atoms.

Question 5: What is the chemical symbol for the element with the atomic number 6? A) N B) O C) C D) H

Explanation: The correct answer is C) C. The chemical symbol for the element carbon is “C,” and it has an atomic number of 6.

Question 6: What is the process of a substance changing from a gas to a liquid? A) Condensation B) Evaporation C) Sublimation D) Vaporization

Explanation: The correct answer is A) Condensation. Condensation is the process by which a substance changes from a gas to a liquid as it loses heat energy.

Question 7: Which type of reaction involves the combination of two or more substances to form a single product? A) Decomposition Reaction B) Synthesis Reaction C) Single Replacement Reaction D) Double Replacement Reaction

Explanation: The correct answer is B) Synthesis Reaction. A synthesis reaction, also known as a combination reaction, occurs when two or more substances react to form a single product.

Question 8: What is the molar mass of a substance measured in grams per mole called? A) Molar Concentration B) Molar Volume C) Molar Density D) Molar Mass

Explanation: The correct answer is D) Molar Mass. Molar mass is the mass of a substance in grams per mole and is numerically equal to its molecular weight.

Question 9: Which type of solution has a higher concentration of solute than the maximum solubility at a given temperature? A) Saturated Solution B) Unsaturated Solution C) Supersaturated Solution D) Concentrated Solution

Explanation: The correct answer is C) Supersaturated Solution. A supersaturated solution contains a higher concentration of solute than is normally possible to dissolve at a given temperature.

Question 10: Which process involves the movement of solvent molecules through a semipermeable membrane to equalize concentrations? A) Filtration B) Distillation C) Osmosis D) Sublimation

Explanation: The correct answer is C) Osmosis. Osmosis is the movement of solvent molecules from an area of lower solute concentration to an area of higher solute concentration through a semipermeable membrane.