Helium which has a chemical formula of He is considered as
a noble gas while Nickel which has a chemical formula of Ni is considered as
metallic. Although both have different phases but they are both classified under
the general category of “Elements”.
 
answer:
<span>elements</span>
 
        
             
        
        
        
The alkali metals are first column, alkali earth 2nd, halogens 2nd to last, and noble gases last. Hope it helps!
        
             
        
        
        
Answer:
When the sun, moon, and Earth are in alignment (at the time of the new or full moon), the solar tide has an additive effect on the lunar tide, creating extra-high high tides, and very low, low tides—both commonly called spring tides.
 
        
             
        
        
        
the big number describes the number ratio in a chemical equation
so for example,
2H2 + O2 --> 2H2O means
2 moles of hydrogen reacts with one mole of oxygen to form 2 moles of water
and as you know, the small (subscript) number determines the number of atoms of that element in one molecule of a compound
so I believe that drawing a normal lewis structure ( O=O ) should be correct