The correct order of basicity of oxides of vanadium is
A particle is moving along x-axis with its position ($ x $) varying with time ($ t $) as:
$ x = \alpha t^4 + \beta t^2 + \gamma t + \delta. $
The ratio of its initial velocity to its initial acceleration, respectively, is:
Lanthanoids are at the top of these two-row, while actinoids are at the bottom row.
Lanthanoids are inclusive of 14 elements, with atomic numbers 58-71:
These elements are also called rare earth elements. They are found naturally on the earth, and they're all radioactively stable except promethium, which is radioactive. A trend is one of the interesting properties of the lanthanoid elements, called lanthanide contraction.