The periodic table is divided into four main blocks based on the electron configurations of the elements. These blocks are:
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s-block:
- Contains Groups 1 and 2 (the alkali metals and alkaline earth metals) and helium (Group 18).
- The elements in this block have their outermost electrons in the s orbital.
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p-block:
- Contains Groups 13 to 18 (the boron group, carbon group, nitrogen group, oxygen group, halogens, and noble gases).
- The elements in this block have their outermost electrons in the p orbital.
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d-block:
- Contains Transition Metals, which are found in Groups 3 to 12.
- The elements in this block have their outermost electrons in the d orbital.
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f-block:
- Contains the lanthanides (elements 57 to 71) and actinides (elements 89 to 103).
- The elements in this block have their outermost electrons in the f orbital.
Summary of Groups in Each Block:
- s-block: Groups 1 (alkali metals), Group 2 (alkaline earth metals), and helium (Group 18).
- p-block: Groups 13 (B), 14 (C), 15 (N), 16 (O), 17 (halogens), and 18 (noble gases).
- d-block: Transition metals (Groups 3 to 12).
- f-block: Lanthanides (elements 57-71) and actinides (elements 89-103).
Each of these blocks corresponds to the type of atomic orbital that the outermost electrons occupy, which reflects the chemical properties and behavior of the elements.