A. Atoms. Because I learned this in 6th grade.
        
             
        
        
        
Explanation:
Solubility is defined as a property of solutes by virtue of which they get dissolved in a favorable solvent. The solute can only be dissolved in any suitable solvent up to a limit at a given temperature. This is a characteristic of the the solute-solvent pairing.
 
        
                    
             
        
        
        
Alpha partical is a He nucleus. When decaying alpha particle mass is reduced by 4 and atomic number is reduced by 2.
The actual element which has 102 protons is No (Nobelium). 
Since it has 167 neutrons, the mass = protons + neutrons = 102 + 167 = 269
after an alpha decay, the new element formed has 100 protons which is Fm ( Fermium)
the alpha decaying equation is,
    ₁₀₂²⁶⁹No → ₁₀₀²⁶⁵Fm + ₂⁴α + heat
the total mass and the atomic number( numbe rof protons) must be equal in both sides.