Fill in the blanks- ______ and ______ can be grown in sandy soil.

Explanation

Metals react with water and produce a metal hydroxide or oxide and hydrogen gas. But all metals do not react with water.
(i) Metals like.potassium and sodium react violently with cold water the reaction is so violent .that the evolved hydrogen immediately catches fire.
`underset("Potassium")(2K(s))+ underset("water")(2H_(2)O(l)) to underset("Potassium hydroxide")(ZnCl_(2))+ underset("Hydrogen")(H_(2))`
`underset("Sodium")(2Na(s))+ underset("water")(2H_(2)O(l)) to underset("Sodium hydroxide")(2NaOH(aq))+ underset("Hydrogen")(H_(2)(g))`
The reaction of calcium is less violent with water.
`underset("Calcium")(Ca(s))+ underset("water")(2H_(2)O(l)) to underset("Calcium hydroxide")(2Ca(OH)_(2)(aq))+ underset("Hydrogen")(H_(2)(g))`
(ii) Magnesium reacts very slowly with cold water but reacts rapidly with hot boiling water to form magnesium oxide and hydrogen gas.
`underset("Magnesium")(Mg(s))+ underset("water")(2H_(2)O(l)) to underset("Magnesium hydroxide")(MgO)+ underset("Hydrogen")(H_(2))`
(iii) Zinc reacts only with steam to form zinc oxide and hydrogen gas.
`underset("Zinc")(Zn(s))+ underset("water")(H_(2)O) to underset("Zinc")(ZnO)+ underset("Oxide")(H_(2))`
(iv) Iron metal react with water only when steam is passed over red hot iron to produce iron oxide and hydrogen gas.
`underset("Iron")(3Fe(s))+ underset("steam")(4H_(2)O) to underset("(Red hot)")(underset("Iron oxide")(ZnO))+ H_(2)`
(v) Copper does not react with water even under drastic conditions. The order of reactivity of above metals with water is same as that with oxygen. i.e.
`Na gt Mg gt Zn gt Fe gt Cu`