Write the difference between the reaction of Calcium and Aluminium with water.

Both gives hydroxides, but

Calcium reacts with water to give calcium hydroxide Ca(OH)2. this product is slightly soluble in water.

Aluminium  is less reactive than Ca, so it reacts with only steam, to give aluminium hydroxide Al(OH)3. This product is insoluble in water.

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume