Question

Which of the following statement is correct regarding an element having atomic number 79?

• A. Its first ionisation enthalpy is maximum in its group
• B. Its first ionisation enthalpy is minimum in its group
• C. It belongs to group 10 of periodic table
• D. It belongs to 5\(^\text{th}\) period of periodic table

Hint:

First ionisation enthalpy increases across a period and is higher for elements with a stable electron configuration, like gold.

Answer 1

The Correct Option is A

Step 1: Element with atomic number 79.
The element with atomic number 79 is Gold (Au). Gold belongs to group 11 and period 6 of the periodic table. Step 2: Ionisation energy trend.
In the periodic table, ionisation enthalpy generally increases across a period and decreases down a group. However, for elements like gold, the first ionisation enthalpy is maximum in their group due to the stable electron configuration and the relatively smaller size of the atom compared to other metals in the same group. Step 3: Conclusion.
Thus, the correct statement is that gold’s first ionisation enthalpy is maximum in its group. Final Answer: \[ \boxed{\text{Its first ionisation enthalpy is maximum in its group}} \]