Atoms, Elements, and Compounds Quiz

What is the simplest part of an element that can exist?

• Molecule

• Atom

• Compound

• Mixture

Where can we find information about elements?

• In a physics journal

• In a biology lab

• On the periodic table

• In a chemistry textbook

What is a key characteristic of a chemical reaction?

• It involves a change in energy

• It only occurs in liquids

• It always produces light

• It never produces new substances

What defines a compound?

• A mixture of different substances

• A single element in a gaseous state

• Two or more elements chemically combined in fixed proportions

• Two or more elements physically combined

What happens when sodium reacts with chlorine?

• They form hydrogen gas

• They form oxygen gas

• They form sodium chloride

• They form water

What is the result of hydrogen reacting with oxygen?

• Methane

• Carbon dioxide

• Hydrogen peroxide

• Water

In a water molecule, what is the ratio of hydrogen to oxygen atoms?

• 1:2

• 3:1

• 2:1

• 1:1

What is the ratio of magnesium to chlorine in magnesium chloride?

• 2:3

• 2:1

• 1:2

• 1:1

How many oxygen atoms are there for every two aluminum atoms in aluminum oxide?

• One

• Four

• Two

• Three

What is a common property of compounds?

• They can be easily separated into elements

• They are always gases

• They are formed by elements in fixed proportions

• They do not involve chemical reactions