Periods are types of elements.
The periodic table is an orderly arrangement of elements based on their atomic number, electron configuration, and chemical properties. It organizes elements into groups and periods to show trends in their behavior and properties.
The horizontal rows are called periods, there are 7. The vertical rows are groups and there are 18.
The periodic table has 7 periods and 18 groups. The periods are in a horizontal line and the groups are in a straight line like up to down.
118 elements are in the periodic table of elements; some of them are still unnamed (January 2013).
112 elements have been named and additional 6 elements have been tentatively proposed.
Because the elements that have similar properties are arranged in groups - or 'periods'.
a Periodic Table organises the different elements, according to the atoms' mass, type, properties, reactivity etc. See the question about: periodic table patterns
7The Periodic Table has 7 periods and 18 groups.
It is arranged such that similar elements with similar preferred bonding arrangements are aligned vertically. This exposes the various s, p, d, and f bonding orbitals for each successive "exterior" shell, and so appears to repeat... hence "periodic".
Periods in the periodic table represent the horizontal rows that classify elements based on the number of electron shells in their atomic structure. Each period corresponds to a new energy level or shell in the electron configuration of the elements.
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The periodic table is an orderly arrangement of elements based on their atomic number, electron configuration, and chemical properties. It organizes elements into groups and periods to show trends in their behavior and properties.
The horizontal rows are called periods, there are 7. The vertical rows are groups and there are 18.
The periodic table has 7 periods and 18 groups. The periods are in a horizontal line and the groups are in a straight line like up to down.
118 elements are in the periodic table of elements; some of them are still unnamed (January 2013).
112 elements have been named and additional 6 elements have been tentatively proposed.
the horizontal rows (not groups) are known as periods.