A student obtained the following data: Mass of beaker 25.87 g
Mass of beaker with mixture sample 28.12 g
Mass of evaporating dish 146.36 g
Mass of evaporating dish with dried salt 147.10g
Mass of beaker with dried salt ???

However, this student spills her sand sample out of the evaporating dish before weighing it. If the student believe in the Law of Conservation of Mass, what should have been the weight of the beaker with the dried sand in it?

26.61 g

Explanation:

The mass of dried salt can be calculated from the mass difference between the evaporating dish with and without dried salt:

And the mass of the beaker with dried salt would thus be:

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