Quiz on Atoms and Compounds

What is the smallest unit of an element that has its chemical identity?

• Molecule

• Atom

• Compound

• Proton

What is an element?

• A substance made of two or more different atoms

• A substance that contains only one type of atom

• A mixture of atoms and molecules

• A compound

Which of the following is NOT an element?

• Oxygen

• Hydrogen

• Water

• Gold

Which of the following is an example of a compound?

• Iron (Fe)

• Oxygen (O₂)

• Water (H₂O)

• Gold (Au)

Which statement is true about compounds?

• Compounds can be separated into elements by physical means.

• Compounds contain atoms of only one element.

• Compounds can be broken down into simpler substances by chemical changes.

• Compounds do not have a fixed composition.

Which of the following statements is true for elements?

• They are made of only one type of atom.

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

• They are made of more than one type of atom.

• They are represented by chemical formulas.

What is the total number of elements discovered so far?

• 92

• 100

• 108

• 118

Which of the following is an example of a compound?

• Gold (Au)

• Oxygen (O₂)

• Sodium chloride (NaCl)

• Silver (Ag)

What is the periodic table?

• A chart that organizes all known elements by their atomic number.

• A list of all discovered compounds.

• A classification of metals only.

• A method to separate mixtures.

What are the vertical columns in the periodic table called?

• Rows

• Periods

• Groups

• Series