Atoms and Molecules
Which of the following is a compound and not an element?
A) Oxygen
B) Nitrogen
C) Iron
D) Water
D) Water
What do we call the process of a liquid becoming a gas?
A) Melting
B) Freezing
C) Evaporation
D) Condensation
C) Evaporation
Which property describes how much space an object occupies?
A) Mass
B) Volume
C) Weight
D) Density
B) Volume
What is the basic formula for calculating density?
A) Mass × Volume
B) Mass ÷ Volume
C) Volume ÷ Mass
D) Weight × Volume
B) Mass ÷ Volume
What type of mixture is formed when sugar dissolves in water?
A) Suspension
B) Colloid
C) Solution
D) Emulsion
C) Solution
What is a molecule?
A) A group of atoms bonded together
B) A charged particle
C) A solid atom
D) An electron and a proton combined
A) A group of atoms bonded together
Which state of matter has a definite shape and volume?
A) Solid
B) Liquid
C) Gas
D) Plasma
A) Solid
Which of the following is a physical property of matter?
A) Flammability
B) Reactivity with acid
C) Color
D) Ability to rust
C) Color
If an object floats in water, what can you infer about its density?
A) It has a higher density than water
B) It has the same density as water
C) It has a lower density than water
D) Its density is zero
C) It has a lower density than water
What is the solvent in a saltwater solution?
A) Salt
B) Water
C) Air
D) Sand
B) Water
How many atoms are there in one molecule of CO₂?
A) 1
B) 2
C) 3
D) 4
C) 3 (1 carbon + 2 oxygen)
What happens to the particles of a substance as it melts?
A) They become still
B) They move further apart
C) They stop moving
D) They break apart into atoms
B) They move further apart
What does it mean if a material is brittle?
A) It stretches easily
B) It is easily shaped
C) It breaks or shatters easily
D) It conducts heat well
C) It breaks or shatters easily
If you cut an object in half, what happens to its density?
A) It becomes half
B) It doubles
C) It remains the same
D) It becomes zero
C) It remains the same
Which of the following best describes a colloid?
A) Solute settles to the bottom
B) Particles are invisible and never settle
C) Particles scatter light and do not settle
D) A type of homogeneous solution
C) Particles scatter light and do not settle
Which particle determines the atomic number of an element?
A) Neutron
B) Electron
C) Proton
D) Mass number
C) Proton
Which state of matter conducts electricity and is made of ions?
A) Solid
B) Liquid
C) Plasma
D) Gas
C) Plasma
Which property refers to how easily a material can be hammered into sheets?
A) Ductility
B) Flexibility
C) Malleability
D) Elasticity
C) Malleability
Which of these will sink in water (density = 1 g/cm³)?
A) Object with density 0.9 g/cm³
B) Object with density 1.0 g/cm³
C) Object with density 1.1 g/cm³
D) Object with density 0.5 g/cm³
C) Object with density 1.1 g/cm³
What is an emulsion?
A) A type of gas mixture
B) A solid-solid mixture
C) A mixture of two immiscible liquids
D) A sugar-water solution
C) A mixture of two immiscible liquids
What is the name of the particle formed when atoms lose or gain electrons?
A) Molecule
B) Ion
C) Neutron
D) Proton
B) Ion
What process changes a solid directly into a gas?
A) Condensation
B) Melting
C) Sublimation
D) Freezing
C) Sublimation
What do we call a substance that can be drawn into wires?
A) Elastic
B) Conductive
C) Malleable
D) Ductile
D) Ductile
What are the standard units for density in the metric system?
A) Grams per liter
B) Grams per milliliter
C) Kilograms
D) Liters per gram
B) Grams per milliliter
Which of the following is NOT a physical method of separating mixtures?
A) Filtration
B) Distillation
C) Electrolysis
D) Chromatography
C) Electrolysis