The periodic table is organized by
A number of neutrons
B atomic number
C Alphabetical order
D atomic mass
The correct answer and explanation is:
The correct answer is B) atomic number.
The periodic table is primarily organized by the atomic number of the elements. The atomic number refers to the number of protons in an atom’s nucleus and is a unique identifier for each element. This organization is crucial because elements with similar chemical properties tend to occur at regular intervals when arranged by atomic number.
The periodic table’s structure is such that elements are placed in rows (called periods) and columns (called groups or families). Elements in the same group have similar chemical properties due to having the same number of electrons in their outer shell. The arrangement by atomic number allows scientists to easily predict the behavior of elements, their reactivity, and their bonding patterns.
It is important to note that early versions of the periodic table were sometimes organized by atomic mass, which led to inconsistencies. For example, iodine and tellurium were swapped in Mendeleev’s original table because of discrepancies in their atomic masses. However, modern understanding of atomic structure clarified that the atomic number, not the mass, is the correct basis for the arrangement of elements.
Furthermore, the periodic table is also structured to highlight trends in element properties. For example, elements on the far-left side tend to be metals, and those on the far-right side are non-metals. The transition elements, located in the middle, are known for having partially filled d-orbitals.
In summary, the periodic table is organized by atomic number, which not only correctly arranges elements but also allows the prediction of properties and behaviors of elements based on their position in the table.