Nitrogen (n), oxygen (o), chlorine (cl), neon (ne), and argon (ar) are all elements that occur as a gas at room temperature (20°c). using the periodic table, which pair of gases has the most similar properties?

The  gases  that has the  most similar  properties   is

Neon (Ne)  and  Argon (Ar)

explanation

   From  periodic  table    both Argon (Ar)  and  Neon(Ne)    are element in  group 18   which are referred  to  as  noble  gases.

Noble  gases are  inert since they have eight (8)   valence  electrons ( electrons in their  outermost shell)   which  make them  stable(  neither gain or  lose  electrons)

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.