Write the merits and demerits of Mendeleev periodic table in points and explain each of them in short​

How have the greenhouse gasses increased from the year 2000 to 2018

As we move from left to right across the periodic table, what is the general trend? a) atomic radii increase. b) electronegavitiy decreases. c) nuclear shielding increases. d) metallic character decreases.

Use the half-reactions of the reaction au(oh)3 + hi -> au +i2 +h2o to answer the questions