The elements on the periodic table are listed in increasing atomic number.
Hydrogen is the first element, and has an A.N. of 1. Also, its very interesting how it doesn't need 8 valence electrons to be stable.
The second element is Helium, which has an A.N (atomic number) of two.
False. elements in the same period have the same number of shells while elements in the same group have the same number of valence electrons.
Answer:
the same
Explanation:
due to the law of conservation of mass, the mass will not change
