Question

Argon is used in arc welding because of its

• A. Flammability
• B. Low reactivity with metal
• C. High calorific value
• D. Ability to lower the melting point of metal

Answer 1

The correct option is B

Low reactivity with metal

The explanation for the correct option:

B. Low reactivity with metal

Argon:

• Argon is a noble gas with an atomic number $18$ and an atomic symbol $\mathrm{Ar}$.
• The stability of noble gases is very high.
• Argon is used in arc welding as it shows low reactivity with metals.
• During welding, there is no chemical change. But at high temperatures, the metals react with atmospheric oxygen to form oxides.
• As argon is an unreactive inert gas thus there is no reaction between argon and the welded metal.

The explanation for incorrect options:

A. Argon gas is inflammable.

C. Argon gas has a low calorific value.

D. Argon does not have the ability to lower the melting point of the metal.

Hence, the correct option is B i.e. low reactivity with metal.