Chemical Sciences (Matter and Materials) Flashcards

Which of these is a chemical change?

Answer: An iron nail rusting

Rusting forms a new substance (iron oxide), so it is a chemical change.

How do particles in a gas compare with particles in a solid?

Answer: They are far apart and move freely

Gas particles are widely spaced and move rapidly in all directions.

Which is an example of sublimation?

Answer: Dry ice turning directly into gas

Sublimation is a solid changing directly into a gas without becoming a liquid.

Which mixture can be separated using filtration?

Answer: Sand and water

Filtration traps insoluble solids like sand while the water passes through.

A block has a mass of 40 g and a volume of 20 cm³. What is its density?

Answer: 2 g/cm³

Density = mass ÷ volume = 40 ÷ 20 = 2 g/cm³.

Water droplets form on the outside of a cold glass of lemonade. What process causes this?

Answer: Condensation

Water vapor in the air cools on the glass and turns into liquid water.

Which property is most important for the handle of a cooking pan?

Answer: Low thermal conductivity

A handle should be a poor heat conductor so it stays cool to touch.