The third one is correct, not sure abt another one
Multiplying the subscripts within the empirical formula by this number gives you the molecular formula H2O2.
Answer:
elements in same group have same valence electron.
period of element is equal to valence shell
Explanation:
if the elements are in a same group then they will be having same number of valence electron.
the period of an element in periodic table is equal to the valence shell of the element. that is if the valence electron are in 3 rd shell then the element will be in third period.
Solid! The molecules in solid matter are arranged closely together and packed quite tightly to maintain a regular shape. Hope this helps!
