Elements R12

What is the smallest unit of an element that maintains the properties of that element?

• Compound

• Atom

• Molecule

• Mixture

Which of the following is a pure substance made of two or more elements that are chemically combined?

• Mixture

• Solution

• Compound

• Suspension

What do you call a substance that consists of two or more substances mixed together but not chemically combined?

• Element

• Compound

• Mixture

• Molecule

Which of the following is NOT a characteristic of a compound?

• Has a fixed composition

• Can be separated by physical means

• Made of elements in a specific ratio

• Has properties different from its component elements

What is the correct representation for a molecule of water?

Which of the following is an example of a mixture?

• Salt (NaCl)

• Water (H₂O)

• Air

• Carbon Dioxide (CO₂)

How many atoms are in a single molecule of carbon dioxide (CO₂)?

• 1

• 2

• 3

• 4

Which of the following is a characteristic feature of mixtures?

• They have chemical bonds between their components.

• They have components that retain their original properties.

• They are always homogeneous.

• They cannot be separated into their components.

Which of the following statements is true about elements?

• They can be broken down into simpler substances by chemical means.

• They are composed of only one kind of atom.

• They are a type of compound.

• They are always liquids at room temperature.

• 6

• 12

• 18

• 24