A period on the periodic table is a horizontal grouping of elements running from the left to right of the table. Several trends are observed going from the left side of the periodic table to the right. More »

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The periodic table of elements is a chemistry reference that lists elements by increasing atomic number, which typically correlates to their atomic masses. The atomic number increases from left to right as well as from t... More »

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The periodic table arranges the known elements in order of increasing atomic number, which typically coincides with increasing atomic mass. Different rows on the table are known as periods. The period number assigned to ... More »

The observed periodic trends in electron affinity are that electron affinity will generally become more negative, moving from left to right across a period, and that there is no real corresponding trend in electron affin... More »

The Roman numerals on a periodic table of elements define the chemical group of the elements in that column and identify the number of valence electrons of each element. Group IA elements have one valence electron; group... More »

In a color-coded periodic table of the elements, the box for each element is colored. This color represents the classes of elements, which include metals, metalloids and non-metals. In general, the color blue is used for... More »

The heaviest metal on the periodic table of elements is osmium. Its density is 22.57 grams per cubic centimeter, which is twice that of the element lead. A quarter-gallon of osmium weighs 50 pounds when compared to a qua... More »