Give the chemical symbol or name for the following elements, as appropriate: c. potassium

Classify each of the following as a pure substance or a mixture. If a mixture, indicate whether it is homogeneous or heterogeneous: (d) sawdust.

Classify each of the following as a pure substance or a mixture. If a mixture, indicate whether it is homogeneous or heterogeneous: (c) a hardboiled egg

In the process of attempting to characterize a substance, a chemist makes the following observations: The substance is a silvery white, lustrous metal. It melts at 649 °C and boils at 1105 °C. Its density at 20 °C is 1.738 g/cm³. The substance burns in air, producing an intense white light. It reacts with chlorine to give a brittle white solid. The substance can be pounded into thin sheets or drawn into wires. It is a good conductor of electricity. Which of these characteristics are physical properties, and which are chemical properties?

You are hiking in the mountains and find a shiny gold nugget. It might be the element gold, or it might be “fool’s gold,” which is a nickname for iron pyrite, FeS₂. Which of the following physical properties do you think would help determine if the shiny nugget is really gold—appearance, melting point, density, or physical state?

Give the chemical symbol or name for each of the following elements, as appropriate: a. carbon

Classify each of the following as a pure substance or a mixture. If a mixture, indicate whether it is homogeneous or heterogeneous: (b) sugar crystals