Answer: Option (D) is the correct answer.
Explanation:
The given elements Li, C and F are all second period elements. So, when we move from left to right across a period then there occurs increase in number of valence electrons as there occurs increase in total number of electrons.
So, it means more electrons are added to the same energy level.
Thus, we can conclude that a property of valence electrons for each element is located in the same energy level is common in the given elements.
Speed can be thought of as the rate at which an object covers distance. ... Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second, but the most common unit of speed in everyday usage is the kilometre per hour or, in the US and the UK, miles per hour........?