Students are given a solid sample and asked to determine whether the sample is an element, compound, or mixture. One student observes that the sample is: made up of particles of different colors, sizes, and shapes
some particles are softer than others
some shine while others appear dull
What can the students conclude about their sample?

It is an element.

It is a compound.

It is a homogeneous mixture.

It is a heterogeneous mixture.

Compound

Explanation:

answer by yourhope:

how do models compare to real-world objects?

d. most models represent a real-world object in a simpler way.

: )

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.

that's it!

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~ trueboss72