The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...

Atomic numbers were not yet known, but the atomic weights worked well enough for ordering most of the elements, and Mendeleev was able to accurately predict the properties of missing elements. John ...

This leads us to ask an important question: Is there a maximum number of elements included in the periodic table? The answer ...

The atomic number of tellurium is 52 and the atomic number of iodine is 53, so these elements are in the correct order in the modern periodic table.

This video is an interactive lesson in calculating an atom’s mass and atomic number. Atoms consist of a nucleus containing protons and neutrons, surrounded by electrons in shells. The numbers of ...

The periodic table of elements is a landmark categorization ... It arranges all natural and synthetic elements by their ...

In this activity, students will use the online periodic table, ptable.com, to investigate a number of chemistry concepts. Students will use this online resource to explore information about the ...

You'll find it on the wall of nearly every school chemistry laboratory in the land. And generations of children have sung the words, "hydrogen and helium, lithium, beryllium..." in an attempt to ...

The finished puzzle is a section of the periodic table, so the numbers on each tile are their atomic numbers - that means they increase from left to right and top to bottom. Another helpful clue ...

A still from the recent season of the BBC's Sherlock showed the world's only "consulting detective" was relying on a 19th century version of the periodic table of the elements. The Royal Society of ...