2G. Which measurement contains a total of three significant figures? *

In this chemical reaction, 325 grams of barium (ba) react completely. how many moles of lithium (li) are produced?

Can someone me with 3 and 4 plz. this is for masteries test.

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?