A) a column
example: earth alkaline metals
I think it is the first option!
ANSWER I think its B
Explanation:
It is based on the size of seimetic waves
5 how bout thathxhzhddhdvsvvssg
Ndeed, most of the alkene<span> addition </span>reactions<span> discussed earlier also take place ... This behavior is nicely </span>explained<span> by differences in the stages of the </span>hydrogenation reaction<span>. ... For </span>examples<span> and a discussion of </span>mechanisms<span> click here. ... to double bonds which </span>give<span> alcohol products, </span>addition of water<span> to alkynes </span>gives<span> ketone ...</span>