Introduction to Representing Elements and Compounds in Chemistry

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

• Molecule

• Atom

• Compound

• Electron

Which of the following is the correct chemical symbol for sodium?

• S

• Na

• Sd

• So

What does the formula H2 indicate about hydrogen molecules?

• They contain one oxygen atom.

• They contain two hydrogen atoms.

• They contain one hydrogen atom.

• They contain two oxygen atoms.

How are compounds formed?

• By splitting elements

• By chemical reactions combining elements

• By mixing elements physically

• By heating elements

What is the chemical formula for water?

• OH2

• H2O

• H2O2

• HO2

In a chemical equation, what does the arrow represent?

• The speed of the reaction

• The conservation of mass

• The equality of reactants and products

• The direction of the reaction

Why is it important to balance chemical equations?

• To ensure the reaction is fast

• To increase the temperature

• To reduce the number of reactants

• To conserve the number of atoms