Matter, Elements, and Compounds Flashcards
7 cards from real BECE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Matter, Elements, and Compounds flashcards as text
How can a mixture be distinguished from a compound?
Answer: Mixtures can be separated by physical means
Mixtures can be separated by physical methods like filtration or magnetism, while compounds require chemical reactions to separate.
Which of the following is a heterogeneous mixture?
Answer: Soil
Soil is heterogeneous because its composition is not uniform — different particles of sand, clay, and organic matter are visible.
What method would best separate a mixture of iron filings and sand?
Answer: Using a magnet
A magnet attracts iron filings but not sand, making magnetic separation the most effective method.
Air is classified as a mixture rather than a compound because:
Answer: Its components can be separated and their proportions vary
Air has variable composition (proportions of N₂, O₂, CO₂, etc. vary) and its components can be physically separated.
Which separation technique works best for recovering dissolved salt from salt water?
Answer: Evaporation
Evaporating the water leaves behind the dissolved salt as solid crystals.
When iron and sulfur are heated together and form iron sulfide, what evidence shows a compound — not a mixture — was formed?
Answer: The new substance has different properties from either iron or sulfur
Iron sulfide cannot be separated by a magnet and has different properties from iron and sulfur, confirming it is a compound.
Which of the following best describes a homogeneous mixture?
Answer: A mixture with uniform composition throughout
A homogeneous mixture has the same composition and properties throughout, such as salt water or air.