D. Ratio of Neutrons to Protons
Answer:
A. Generally ionic compounds are formed metal and non metal elements since they forms opposite charged ions due to difference in their Electronegativity values.
NaCl, MgCl2, Ca(OH)2 etc are ionic compounds.
B. Generally transition elements (D elements) forms cations with different charges or simply they exist in different oxidation states due to availability of empty d orbitals.
Examples are Iron exsits as Fe+2 and Fe+3
Mn exists as Mn+2 , Mn+4, Mn+6 ,Mn+7 etc.
The trick for this problem is to understand atomic mass: the fact that different atoms have different masses. What we need to do is add up all the atomic masses of the compound and work out the ratio of mass of water to the mass of sodium carbonate. Atomic masses are often given for each atom in the periodic table, but you can look them up on google too.
You can do this by adding up individual atoms for each molecule, or you can shortcut and lookup the molar mass of the compound (i.e.the task already done for you).
The molar mass of water is 18.01g/mole so for 10 moles of water we have a mass of 180.1g.
The molar mass of sodium carbonate is 106g/mole (google).
So the total mass of the sodium carbonate decahydrate compound is 180.1+106 = 286.1g, of which water would make up 180.1g, so the percentage of water is is 180.1/286.1 = 0.629, so we can round this to 63%
:)
Solid gold. 10 carat indicates gold purity is not 100%. For 24 karat gold is pure gold.
