If 100 grams of iron react with 90 grams of oxygen and 130 grams of iron(III)oxide is produced, then what is the percent yield? PLEASEE HELPPP!!

If a simple machine aduces the strength of a force, what must be increased? the speed of the input force the work the simple machine performs the size of the simple machine the distance over which the force is applied

What must be in balance for temperatures to remain constant?

Ascientist wants to know how individual lions within a pride interact with each other in their own environment. to do this, the scientist sedates and tags all of the lions within a pride. then, he places several remotely-controlled video cameras near the lions' den and performs an observational field study. he collects continuous video footage over the span of one year, analyzes the video, and then forms conclusions based on his observations.