Chemistry 8

Which of the following best describes a compound?

• A substance made of only one type of atom that cannot be broken down by chemical means.

• A physical blend of two or more substances that can be separated by physical methods.

• A substance made of two or more different types of atoms chemically bonded in a fixed ratio.

• A group of the same atoms loosely held together in no specific proportion.

Which method would best separate sand from salt water?

• Evaporation

• Filtration

• Magnetism

• Decantion

Which of the following is an example of a compound?

• O₂ – two oxygen atoms bonded together

• H₂O – two hydrogen atoms and one oxygen atom chemically bonded

• Na – a single element

• Salad – a mixture of different substances

Which of the following is an example of a chemical property of matter

• Density

• Color

• Flammability

• Melting Point

What do elements in the same group (family) have in common?

• Similar chemical properties

• Same atomic number

• Same number of protons

• Same mass

What is the correct electron configuration for Carbon?

• 1s² 2s² 2p²

• 1s² 2s¹ 2p³

• 1s² 2s² 2p⁴

• 1s² 2s² 2p⁶

Arrange the following elements in order of increasing ionization energy: Na, Mg, Al

• Al < Mg < Na

• Mg < Al < Na

• Na < Al < Mg

• Na < Mg < Al

Which of the following best describes covalent compounds?

• High melting points, conductive

• Low melting points, brittle, not conductive

• Malleable, shiny, ductile

• Brittle, conducts electricity when dissolved

What do the dots around an element's symbol in a Lewis diagram represent?

• Protons

• Neutrons

• Core electrons

• Valence electrons

What does the Law of Conservation of Mass state?

• Mass can disappear in a chemical reaction

• Atoms can be created or destroyed

• The total mass of reactants equals the total mass of products

• Products are always heavier than reactants