Question

identify each substance as either an element, a compound, a homogeneous mixture or a heterogeneous mixture. (answer choices can be used more than once or not at all)
a. carbon dioxide (co₂)
b. gold (au)
c. pizza
d. distilled/pure water
e. stainless steel (a metal alloy)

carbon dioxide choose
gold choose
pizza choose
distilled water choose
stainless steel choose
desk 1

Explanation:

• Carbon dioxide (CO₂): A compound is a substance made of two or more different elements chemically bonded. CO₂ has C and O bonded, so it's a compound.
• Gold (Au): An element is a pure substance with only one type of atom. Gold is made of Au atoms, so it's an element.
• Pizza: A heterogeneous mixture has visibly different components (like toppings, dough, sauce) that aren't uniformly mixed. Pizza has distinct parts, so it's a heterogeneous mixture.
• Distilled water: Pure water (H₂O) is a compound as it has H and O atoms chemically bonded in a fixed ratio.
• Stainless steel (alloy): A homogeneous mixture (solution) of metals (like Fe, Cr, Ni) with uniform composition at the microscopic level, so it's a homogeneous mixture.

Answer:

• Carbon dioxide: Compound
• Gold: Element
• Pizza: Heterogeneous Mixture
• Distilled water: Compound
• Stainless steel: Homogeneous Mixture