Answer:
••It's melting point equals -38.8 degrees Celsius because it is mercury. |••
Explanation:
This one makes the most sense out of the answers. 
 
        
             
        
        
        
A rapid release of stored up energy 
        
                    
             
        
        
        
Strontium (Sr). Elements in the same group of the periodic table have similar characteristics. 
 
        
                    
             
        
        
        
Answer:
1.12 × 10⁻⁴ M
Explanation:
Step 1: Write the reaction for the solution of Mg(OH)₂
Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)
Step 2: Make an ICE chart
We can relate the solubility product constant (Ksp) with the solubility (S) through an ICE chart.
        Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)
I                                0                    0
C                              +S                +2S
E                                S                  2S
The solubility product constant is:
Ksp = 5.61 × 10⁻¹² = [Mg²⁺] × [OH⁻]² = S × (2S)² = 4S³
S = 1.12 × 10⁻⁴ M