Why do elements in a vertical column of the periodic table have similar chemical properties?
a. they possess the same number of outermost electrons.
b. they have similar physical characteristics.
c. they are found in similar locations in nature
d. they have similar atomic masses.

Needthe meter is the standard unit for: 1) height 2) length 3) weight 4) mass

Problem page combustion of hydrocarbons such as pentane ( c5 h12 ) produces carbon dioxide, a "greenhouse gas." greenhouse gases in the earth's atmosphere can trap the sun's heat, raising the average temperature of the earth. for this reason there has been a great deal of international discussion about whether to regulate the production of carbon dioxide.(a) write a balanced chemical equation, including physical state symbols, for the combustion of liquid pentane into gaseous carbon dioxide and gaseous water. (b) suppose 0.350 kg of pentane are burned in air at a pressure of exactly 1 atm and a temperature of 20.0 degree c. calculate the volume of carbon dioxide gas that is produced. be sure your answer has the correct number of significant digits.

Draw two cyclic constitutional isomers of cis-1