PbSO₄ partially dissociates in water. the balanced equation is;
                    
                       PbSO₄(s) ⇄  Pb²⁺(aq) + SO₄²⁻(aq)
Initial                                     -                -
Change             -X               +X           +X
Equilibrium                           X              X
Ksp           =    [Pb²⁺(aq)] [SO₄²⁻(aq)]
1.6 x 10⁻⁸  =    X * X
1.6 x 10⁻⁸  =    X²
          X    =   1.3 x 10⁻⁴ M
      
Hence the Pb²⁺ concentration in underground water is 1.3 x 10⁻⁴ M. 
[Pb²⁺]  = 1.3 x 10⁻⁴ M.
           = 1.3 x 10⁻⁴ mol / L x 207 g / mol 
           = 26.91 ppm
        
             
        
        
        
Answer:
Molar mass of Al2O3 = 101.961276 g/mol
This compound is also known as Aluminium Oxide.
Convert grams Al2O3 to moles or moles Al2O3 to grams
Molecular weight calculation:
26.981538*2 + 15.9994*3
Percent composition by element
Element Symbol Atomic Mass # of Atoms Mass Percent
Aluminium	Al	26.981538	2	52.925%
Oxygen	O	15.9994	3	47.075%
Explanation:
Percent composition by element
Element	Symbol	Mass Percent
Aluminium	Al	52.925%
Oxygen	O	47.075%
 
        
             
        
        
        
<span>The simplest level of organization for living things is a single organelle, which is composed of aggregates of macromolecules. so it is false</span>
        
                    
             
        
        
        
#AB
Electronegativity difference=3.3-2.9=0.4.
- It's a covalent bond.
 - Gaseous or solid substance.
 
#AC
Electronegativity difference=3.3-0.7=2.6
- Its an ionic bond.
 - Solid substance.
 
#BC
Electronegativity difference=2.9-0.7=2.3
- It's an ionic bond
 - Solid substance