Answer:
B.
Explanation:
the SI unit for density is the kilogram per Cubic meter
Answer:

Explanation:
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In this case, for the reaction by which water is decomposed to molecular hydrogen and oxygen:

It is necessary to perform the inspection balance process since there is a dissimilar number of atoms of oxygen on both sides; therefore, by putting a 2 on water we balance oxygen:

But now, there are four hydrogens on the left; therefore, we put a 2 on hydrogen to finally balance it:

And obviously, the coefficient in oxygen is an unwritten 1.
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Active metals are those metals in the group 1 of the periodic table.
Electronegativity is the trend to atract electrons.
Active metals have few valence electron, because their last shell is of the kind ns^1 or ns^2
Then, these atoms do not trend to attract electrons. The most electronegative atomos are those who have 7 valence elecfrons; this is their last shell is of the kind ns^7, because when they attract one electron to its valence shell they will complete 8 electrons which is the most stable configuration.