How many atoms are represented by one formula unit of aluminum chromate, Al2(CrO4)3

17 atoms

Explanation:

If what we want is to calculate the number of atoms. We must take into account the subscripts of the formula. We can rewrite the formula  taking into account the "ones" implicit in the formula, therefore we will have:

Now we have a "3" outside the parenthesis. Therefore, we must multiply this 3 by the number of atoms within the parentheses:

-) Oxygen atoms: 4 x 3 = 12 atoms

-) Chromium atoms: 1 x 3 = 3 atoms.

If we take into account we have 2 aluminum atoms, in total, we will have:

-) 12 oxygen atoms

-) 3 chromium atoms

-) 2 aluminum atoms

12 + 3 + 2 = 17 atoms

In total, we will have 17 atoms.

See figure 1

I hope it helps!

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.