Which statement best describes the process of food digestion in the mouth?

• Chemical changes occur during chewing and saliva breakdown

• Physical changes occur during chewing and chemical changes occur with saliva

• Both processes are physical changes

• Both processes are chemical changes

What is the most basic type of pure substance?

• Molecule

• Element

• Compound

• Mixture

When identifying the state of matter, which characteristics indicate a liquid?

• Fixed shape and fixed volume

• Fixed volume but variable shape

• Variable shape and variable volume

• Fixed shape but variable volume

What happens to water in a pond during seasonal changes from winter to summer?

• Freezing → condensation → evaporation

• Melting → evaporation → condensation

• Freezing → melting → evaporation

• Condensation → freezing → melting

How do surface tension and viscosity compare between water and oil?

• Water has higher surface tension and lower viscosity

• Oil has higher surface tension and higher viscosity

• Water has lower surface tension and higher viscosity

• They have equal surface tension but different viscosity

What type of force is being applied when pushing a shopping cart?

• Gravitational force

• Contact force

• Magnetic force

• Electrical force

How does energy change in a roller coaster at its lowest point?

• Maximum potential energy, minimum kinetic energy

• Maximum kinetic energy, minimum potential energy

What is a key characteristic of heterogeneous mixtures?

• Cannot be separated physically

• Can be separated physically

• Must be chemically separated

• Forms new chemical compounds

Why are synthetic materials important in modern society?

• They are always biodegradable

• They require no natural resources

• They help meet demands when natural materials are scarce

• They are less artificial than natural materials

What happens to gravitational force when distance between objects increases?

• Force increases

• Force stays the same

• Force decreases

• Force becomes zero