What is the percent composition by mass of sulfur in Na2SO4

Draw the skeletal structures of two different molecules that are each made of 5 carbon atoms and 12 hydrogen atoms.

Read "who built the pyramids? ”. leave this link open while you answer the questions throughout the assignment. give at least two reasons why some people claim the pyramids of giza were constructed by aliens.

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.