Calcule cuántos moles hay en 3,0 g de helio (He). Considere la masa molar (MM)del helio como 4,0 g/mol. * 1 mol
2 mol
0.65 mol
0.75 mol

Draw metallic bonding if two copper

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?

Suppose that some of the compound spilled out of the crucible after it was heated. would that cause the percent by mass of water in the compound determined by the experiment to be too low, too high, or unchanged? briefly explain your answer.