What significant aspect of Bohr's model is still relevant in contemporary atomic theory?

• Electrons orbit the nucleus like planets

• Electrons possess specific energies

• Electrons are stationary

• Electrons are positively charged

What is the density of water at room temperature?

• 1 g/cm³

• 2 g/cm³

• 0.5 g/cm³

• 1.5 g/cm³

What is a pure substance?

• A mixture of elements

• Anything that contains matter

• A substance with a fixed composition

• A solution of compounds

What is the Greek letter used to represent density?

• Alpha

• Beta

• Rho

• Sigma

What is the unit of volume in the MKS system?

• Liters

• Cubic meters

• Gallons

• Cubic centimeters

What happens to objects less dense than water?

• They sink

• They float

• They dissolve

• They evaporate

What are the two broad categories of substances?

• Elements and compounds

• Pure substances and mixtures

• Solids and liquids

• Gases and liquids

What is a mixture?

• A single element

• A combination of substances without a chemical reaction

• A compound formed by a chemical reaction

• A pure substance

What is one kind of pure substance?

• Mixture

• Element

• Solution

• Gas

What is the density of water at room temperature?

• 1 g/cm³

• 2 g/cm³

• 0.5 g/cm³

• 1.5 g/cm³