Which option correctly describes a reactant? 1 substance that is burned and destroyed during a chemical reaction 2 substance that enters into a chemical reaction and is changed by that reaction 3 substance that is present during a chemical reaction but is not affected by that reaction 4 substance that forms as a result of a chemical reaction

Use the periodic table to determine the electron configuration of dysprosium (dy) and americium (am) in noble-gas notation.

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?

The chemical formula for emerald is be3al2(sio3)6.an emerald can be decided as