Which of the following is the least reactive metal in the reactivity series?

Correct option is A

The correct answer is (a) Au​

Explanation: Gold (Au) is the least reactive metal in the reactivity series.

Information Booster: Gold is the least reactive metal because:

• Its nucleus is heavy, so electrons must travel at the speed of light
• The 6s electrons in gold are less accessible for bonding
• Their energy is dissimilar to many reactants
  

Here are some other facts about the reactivity series:

• Reactivity- Metals higher in the reactivity series can displace less reactive metals from their compounds.
• Reactions- Reactions between metals and acids can be predicted using the reactivity series. For example, lead and other metals more reactive than lead can react with hydrochloric and sulfuric acid to form salts.
• Extraction- Metals higher in the reactivity series are extracted using methods other than carbon, such as electrolysis. Electrolysis involves passing an electric current through the molten metal ore.
• Francium- Francium is the most reactive element on the periodic table, but it's artificial or only produced in small quantities. After francium, cesium is the most reactive metal.