Question

18
a ___ is a form of matter that has its own definite shape and volume. * (0.5 points)
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19
an _____ is a pure substance that cannot be separated into simpler substances by physical or chemical means. * (0.5 points)
enter your answer
20
after two elements react to completion in a closed container, the ratio of their masses in the container will be the same as before the reaction. which law describes this principle? * (0.5 points)

Explanation:

Question 18

In physics (a subfield of Natural Science), solids are defined as matter with definite shape and volume.

In chemistry (a subfield of Natural Science), an element is a pure substance that can't be broken down into simpler substances by physical or chemical means.

The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction, so the mass ratio remains the same in a closed container.

Answer:

solid

Question 19