Mrs. harrison mixes some chemicals together in a glass beaker in front of her science class. she asks her students to watch for a chemical reaction when she holds it over a bunsen burner. she sets the flame on "low" and holds the beaker a few inches above the heat. after about 30 seconds, the mixture begins to fizz. what could mrs. harrison do to make the chemical change occur faster? a) add twice as much of a chemical in the mixture b) increase the flame setting to produce more heat c) use a smaller beaker with the same amount of chemicals d) add cold water to the mixture to reduce i

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).