The fourth period ends with the element ____

Which of the following is not a Metalloid?

Which was the incomplete period in the long-form of the modern periodic table?

N2O is a _____

3d transition series starts from _____ and ends with ______

In triads, the average weight of the 1st and the 3rd element are equal to the second one.

The element ________ is also known as Unnilunium.

Write the correct electronic configuration of Neon.