The cube has a mass of 72.9 g.

what is its density in g/cm3?

what substance is it?

Why does a plastic bottle that is sealed at a high altitude change it’s shape when taken to lower altitude

What’s the theoretical yield of solid lead

You exhale co2 which is produced during cellular respiration.  co2 combines with the water in your blood's plasma to make up one half of the body's most important buffer pair, carbonic acid.  the more physical activity you engage in, the more co2 your body is producing.  you can see this by putting some of the cabbage indicator in a glass and then blowing bubbles into it through a straw.  can you see a change in the color of the indicator?