Why do scientists use models?

Models make some things easier to understand.
Measurements can be made only on models.
Models help scientists visualize things they can’t see.
Models are perfectly accurate representations of objects.

C. Models help scientists visualize things that they cannot see.

Explanation:

A model is used to help scientists visualize things that they cannot see. A model is used to represent an idea, an object or a process that describes a phenomena. It tends to be thought of a speculation instrument to help structure clarifications.

Models are valuable rearrangements to help understanding. The models are incredible assets however they are legitimate as long as they can clarify the entirety of the accessible information that is from the perceptions and estimations.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

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answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them