Jen wants to make a fair comparison of the reactivity if the metals with hydrochloric acid. What are the 2 variables that must be kept constant?

What are the percent by mass of copper in penny lab

Used the balanced equation 2h2+ o2 - -> 2h2o. if you have 7.2 grams of o2 , how many grams of h2o can you produce ?

Turbo the snail moves across the ground at a pace of 12 feet per day. if the garden is 48 feet away, how many days will it take for the snail to get there?