Question

1. choose all that apply.

which two statements are advantages of a model?
are exactly like the thing they represent
save time and money before making a product
study things that are very small
only an approximation of a phenomenon

1. choose the best answer.

iron oxide (rust) does not contain carbon. iron oxide is a(n) ____ compound.
extensive
intensive
organic
inorganic

Explanation:

• For question 16:
• Models are not exactly like the things they represent (they are approximations). Saying "only an approximation" is a neutral or even a drawback statement in the context of advantages.
• Models can save time and money (e.g., in engineering, a model of a bridge can be tested before building the real bridge).
• Models can be used to study very small things (e.g., molecular models in chemistry).
• For question 17:
• Extensive and intensive are terms related to properties (e.g., extensive property depends on the amount of substance like mass; intensive property does not like temperature).
• Organic compounds contain carbon (with some exceptions like \(CO_2\)). Since iron oxide (\(Fe_2O_3\)) has no carbon, it is inorganic.

Answer:

1. save time and money before making a product, study things that are very small
2. inorganic