Answer:
hardest
Explanation:
Diamonds are known as the hardest naturally occurring substance known.
Answer:
8 (maybe 18)
Explanation:
Depends on whether you have the d orbitals. If not, it's 8, and it's 18 including the d orbitals
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.
According to momentum conservation
15*3 = 45kgm/s
and the velocity of 5 kg mass will be
45/5 = 9 m/s
