the number of atoms in 2.50 mol Cr

1.51 x 10²⁴atoms

Explanation:

Given parameters:

Number of moles of Cr = 2.50mol

Solution;

what is a mole;

  a mole of any substance is the amount of substance that contains the avogadro's number of particles which is 6.02 x 10²³ particles

The particles here can be atoms, protons, neutrons, electrons e.t.c

                   1 mole contains 6.02 x 10²³ atoms

                  2.5 moles will contain  2.5 x 6.02 x 10²³   = 1.51 x 10²⁴atoms

b i think it’s a water wheel turning in a stream

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.