4 points 19. Four mixtures are made by combining two clear liquids, and observations are made. Which mixture demonstrates that a chemical change has occurred? * Mixture 1: The combined liquids have a greater mass than either of the starting liquids. Mixture 2: The liquids, when mixed, produce a white solid, which settles to the bottom. O Mixture 3: The mixture of the two liquids takes the shape of the container. Mixture 4: The denser of the two liquids lies below the other, less dense liquid.​

Which level of taxonomy has the fewest organisms?

Adistinctive characteristic of mammals that is not observed in other vertebrates is

1. an enzyme is considered a(n) because it speeds up a chemical reaction without being used up.2. in a catalyzed reaction, a reactant is often called a(n) . an enzyme is specific because the shape of its matches only particular reactants.4. an enzyme speeds up reactions by lowering the . the between an active site and its substrate often strains bonds and the reaction proceed.6. a( , which is often a vitamin, binds to an enzyme and plays a role in catalysis.7. high temperatures or changes in ph can an enzyme, causing it to lose its shape and biological activity.