Making hydrogen gas for fuel usually involves * -using energy to break down water
-a combustion reaction
-breaking down a hydrocarbon
-a synthesis reaction

In which of the following belong to a category called the main group of elements? nonmetals. transition elements. halogens. alkali metals. it can be more than one answer!

Agas in a balloon at constant pressure has a volume of 160 ml at -125*c. what is its volume at 29.0*c?

Remember to use the proper number of significant figures and leading zeros in all calculations.gelatin has a density of 1.27 g/cm³. if you have a blob of gelatin dessert that fills a 2.0 liter bottle, what is its mass? 2540 g2500 g3.9 x 10-43.937x 10-4