Which of the following statements correctly describes the arrangement of particles in a solid?

• a) Particles are closely packed and vibrate in fixed positions.
• b) Particles move freely and are far apart.
• c) Particles slide past each other but are still close together.
• d) Particles collide randomly with each other in all directions.

Which change of state occurs when a solid turns directly into a gas without becoming a liquid?

• a) Melting
• b) Evaporation
• c) Sublimation
• d) Condensation

What happens to the movement of gas particles when the temperature increases?

• a) They move slower and closer together.
• b) They move faster and further apart.
• c) They remain at the same speed but change direction more often.
• d) They stop moving.

Which of the following explains why gases can be compressed easily?

• a) Gas particles have a strong attraction to each other.
• b) Gas particles are widely spaced apart.
• c) Gas particles do not move.
• d) Gas particles form rigid structures under pressure.

Increasing pressure on a gas at constant temperature will decrease its volume.

Boiling and evaporation are the same process.

The atomic number of an element represents the number of protons in the nucleus.

An atom has 11 protons, 12 neutrons, and 11 electrons. What is its mass number?

• a) 11
• b) 12
• c) 22
• d) 23

Which of the following is an isotope?

• a) Two atoms with different numbers of protons
• b) Two atoms with the same number of protons but different numbers of neutrons
• c) Two atoms with different numbers of electrons
• d) Two atoms with the same number of neutrons but different numbers of protons

Which type of bond is formed when electrons are transferred from one atom to another?

• a) Covalent bond
• b) Ionic bond
• c) Metallic bond
• d) Hydrogen bond

What type of bonding is present in a molecule of water (H₂O)?

• a) Ionic
• b) Metallic
• c) Covalent
• d) Hydrogen

Which of the following substances contains metallic bonding?

• a) NaCl
• b) H₂O
• c) Cu
• d) CO₂

Why do ionic compounds have high melting and boiling points?

• a) They contain weak intermolecular forces.
• b) They have strong electrostatic forces between oppositely charged ions.
• c) They are made up of small molecules.
• d) Their atoms share electrons.

Covalent compounds conduct electricity in molten or aqueous state.

Metallic bonding involves a "sea of delocalized electrons" that allows metals to conduct electricity.

Which of the following is a property of alkali metals (Group I elements)?

• a) Low reactivity
• b) High melting points
• c) Forming +1 ions in reactions
• d) Poor electrical conductivity

Which statement is true about elements in the same group of the periodic table?

• a) They have the same number of protons.
• b) They have the same number of valence electrons.
• c) They have the same atomic mass.
• d) They have the same number of electron shells.

Transition metals have low melting points and are poor conductors of electricity.

Why is fractional distillation used instead of simple distillation to separate ethanol from water?

• a) Ethanol and water mix completely.
• b) Ethanol and water have similar boiling points.
• c) Ethanol dissolves in water.
• d) Ethanol is a gas at room temperature.

What property of substances does paper chromatography rely on?

• a) Boiling point
• b) Solubility and attraction to the paper
• c) Density
• d) Conductivity