A hydrated salt, compound A, is analysed and has the following percentage composition by mass; Cr, 19.51%;

Cl, 39.96%;

H, 4.51%;

O, 36.02%

Calculate the formula of compound A, showing clearly the water of crystallisation.

The modern periodic table has groups.

How many moles of bromine are needed to produce 3.23 moles of potassium bromide

The characteristics of two different types of reactions are shown below: reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of an element. which statement is true about the atoms of the elements that participate in the two reactions? their identity changes in both reaction a and reaction b. their identity changes in reaction a but not in reaction b. their identity changes in reaction b but not in reaction a. their identity remains the same in both reaction a and reaction b.