Scientists’ ideas about atoms have changed over time. Today, they agree that atoms have a positively-charged nucleus made of protons and neutrons, and negatively-charged electrons that orbit the ...

The metal elements are on the left of a ‘stepped line’ that runs below boron (B), silicon (Si), arsenic (As), tellurium (Te), and astatine (At). You can tell the difference between the metals and ...

You may use table navigation commands for the screen reader of your choice. The Periodic Table of Elements. Each entry contains the atomic number, chemical symbol, and atomic mass to two decimal ...

An expanded periodic table shows where researchers expect elements 119 and 120 to be categorized if they are discovered. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news ...

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