Why are phase changes considered physical and not chemical
changes?

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?

Draw a line graph showing the relationship between temperature in kelvin as a function of kinetic energy.

How many moles of no2 will form when 3.3 moles of cu are reacted with excess hno3?