1. What is the molar mass of Al2S3?

Theoretically, which metal should be the most reactive? hydrogen lithium francium fluorine

Express the following number in scientific notation. 0.026890 =

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?