What information does a chemist communicate with a chemical equation?

Which pair supplies the starting substances in the displayed reaction?

Which substance is formed alongside mercury in the reaction shown?

How should the arrow in this equation be read?

Which symbol indicates that a reaction can proceed in both directions?

What does (aq) after a formula tell you about a substance?

Which notation represents water as a liquid?

Magnesium burns in oxygen. Which word equation describes the reaction?

Solid sodium carbonate reacts with aqueous hydrochloric acid, forming liquid water, carbon dioxide gas, and aqueous sodium chloride. Which formula equation matches?

How should the displayed equation be classified?

What must be equal on both sides for a chemical equation to obey conservation of mass?

What does the large number before the displayed formula indicate?

What does the small 4 in the displayed formula specify?

Count the oxygen atoms represented in one formula unit of the displayed compound.

A student balances H₂ + O₂ → H₂O by changing H₂O to H₂O₂. Why is this correction invalid?

What coefficient belongs before HCl to complete the displayed equation?

Choose the lowest whole-number coefficients, in order, for the displayed reaction.

The displayed equation already conserves atoms. Which coefficient ratio is its simplest whole-number form?

Which group contains only elements normally represented by diatomic molecules in chemical equations?

A steel railing in Cebu develops reddish-brown material. Why is this evidence of a chemical change?