The horizontal rows of the periodic table are called ______?
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Answer: B. Periods
Explanation
The horizontal rows of the periodic table of elements are officially designated as periods. Each period corresponds to the sequential filling of electron energy shells in atoms. Moving horizontally across a period reveals predictable trends in chemical reactivity and atomic radius. The periodic table organizes chemical elements based on atomic number and recurring properties. Vertical columns in the table are known as groups or families sharing similar valence electrons. Dmitri Mendeleev created the foundational periodic table layout based on atomic weights.
Chemistry students and researchers use periods and groups to predict elemental bonding behaviors. Modern materials science relies on periodic table trends to discover new semiconductor compounds. Understanding atomic structure helps explain why elements in the same row share physical features. Groups refer specifically to the vertical columns rather than the horizontal rows of elements. Sets and matrices are general mathematical terms not used in standard chemical nomenclature. Distinguishing between rows and periods is essential for accurate chemical classification.
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- Everyday Science
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- Everyday Science
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- medium
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