Six-mark questions are extended open response questions. These require longer answers than the structured questions that have fewer marks. It is wise to plan your answer first by making some notes.

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 ...

IN a letter to NATURE of November 25 last Dr. Norman Campbell discusses the problem of the possible consistency of the assumptions about the motion and arrangement of electrons in the atom ...

Photo: Niels Bohr's research notes for his new atomic theory Rutherford's find came from a very strange experience. Everyone at that time imagined the atom as a "plum pudding." That is, it was ...

This year we celebrate the 150 th anniversary of Mendeleev’s achievement in formulating the structure of the periodic table that we use today. He announced his structure in 1869, but the challenge of ...

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The ACS is making educational resources available by topic to aid parents and teachers during this time of distance learning. The Periodic Table is an amazing chemistry tool that is organized with ...

A new generation of electron microscopes is able to explore the microscopic properties of materials and devices as diverse as transistors, turbine blades and interfacial superconductors.