What is the percent by mass of oxygen in carbon dioxide (co2)?
use

%element=total mass of element in compound/molar mass of compound -x100

27.29%
57.12%
72.71%
79.99%

How to convert a density of 0.791g/cm3 to lb/ft3

According to the kinetic-molecular theory, what happens to a liquid when it is transferred from one container to another? the volume and the shape stay the same. the volume increases to fill the new container, but the shape stays the same. the volume stays the same, but the shape changes to fit the new container. the volume and the shape change to fill the new container.

Need , hurry pls create a superhero out of the element iron, what are its powers and his sidekick ( an element that works well with iron). how was the superhero made and who discovered him