Answer:
no. of water molecules associated to each molecule of 
= 4
Explanation:
Mass of before heating = 19.8 g
Mass of after heating = 12.6 g
Difference in mass of before and after heating
= 19.8 - 12.6 = 7.2 g
Difference in mass corresponds to mass of water driven out.
Molar mass of water = 18 g/mol
No. of moles of water = 
Mass of obtained after heating is mass of anhydrous .
Mass of anhydrous = 12.6 g
Molar mass of = 125.9 g/mol
No. of mol of anhydrous = 
so,
0.1 mol of have 0.4 mol of water
1 mol of will have = 
Hence, no. of water molecules associated to each molecule of = 4
The formula would be MgMn2O8
Aluminum has three electrons in its valence shell. if you look at the periodic table, there are numbers at the top. in column 2, the elements have 2 valence electrons, in column 3 they have 3 valence electrons etc.
Answer:Krypton is a noble gas and has a full valence electron shell, is chemically non-reactive, and located in group 8A
Explanation:krypton are element of group 18(VIIIA) and are refer to as noble gases because they often dont react with other gases. They are in active gases usually not found in large quantity like other elements such as Nitrogen,oxygen...It has six Isotopes/other forms and can be used for filling lamps.
