Question

Which of the given metals exhibits both reactions (a) as well as (b)?

(a) Metal + Oxygen $\to$ Metal oxide

(b) Metal + Cold water or hot water or steam $\to$ Metal hydroxide + Hydrogen

• A. Magnesium (Mg), iron (Fe), sodium (Na), and copper (Cu)
• B. Magnesium (Mg), zinc (Zn), platinum (Pt), and gold (Au)
• C. Sodium (Na), potassium (K), magnesium (Mg) and calcium (Ca)
• D. Copper (Cu), magnesium (Mg), gold (Au), and sodium (Na)

Answer 1

The correct option is C Sodium (Na), potassium (K), magnesium (Mg) and calcium (Ca)

Sodium (Na), potassium (K), calcium (Ca), magnesium (Mg) reacts with oxygen to form their respective metal oxides. These metals being very reactive, react with cold water, hot water and steam. However, magnesium is less reactive than these three and reacts with hot water and steam.

Iron react with both oxygen and steam. Copper (Cu) reacts with oxygen but is unreactive any form of water.

Platinum (Pt) and gold (Au) are unreactive towards both water and oxygen.

Hence, the elements showing both reactions are sodium (Na), potassium (K), magnesium (Mg) and calcium (Ca).