The model of the solar system is way smaller than the real object. The model of sub-atomic particles in a atom is way larger than the real object.
For both of them, used the balanced equation and it’s mole ratio to convert whatever you need to into moles. See the attacked work.
1) D 5 mols
2) A 0.55 mols
Element atomic number position
Ba 56 group 2, period 6
Ca 12 group 2, period 3
S 16 group 16, period 3
Si `14 group 14, period 3
Now, you need to know the properties of the different type of elements and the tendencies on the periodic table.
The metallic elements are, those placed on the left side of the periodic table, are the ones that release an electron more easily, so they will requiere less energy to give it up when forming chemical bonds.
The higher the metallic character the less the energy need to give up an electron.
The metallic character grows as the group number decreases (goes to the left) period increases (goes downward), so among the elements considered, Barium will require the least amount of energy to give un an electron when forming chemical bonds.
C6H6 is the
most insoluble in water as it is non polar in nature. HCL is highly soluble in
water as it is an electrolyte. Kbr is also highly soluble in water. NaCl
dissolves in water very quickly. CH3CH3OH is also totally soluble in water
because of the Hydrogen bonding formation. It is a well known fact that the
hydrocarbons do not easily mix with water. C6H6 being a strong hydrocarbon does
not mix with water. So among NaCl, KBr, CH3CH3OH, HCl and C6H6, the hydrocarbon
is the least soluble in water.
