The periodic table is divided into four blocks: $s$, $p$, $d$ and $f$. State the rule used to assign an element to a block, and name the two series of elements that make up the $f$-block.

The periodic table is divided into four blocks: s, p, d and f. State the rule used to assign an element to a b

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Step 1. Every element's ground-state electronic configuration ends with its last, or 'differentiating', electron entering a specific subshell.

Step 2. If that subshell is $s$ , the element is in the s-block (Groups 1–2); if $p$ , the p-block (Groups 13–18); if $(n-1)d$ , the d-block (Groups 3–12, transition elements); if $(n-2)f$ , the f-block (inner-transition elements).

Step 3. The f-block itself is made of two 14-element series: the lanthanoid series (Period 6, cerium to lutetium, filling $4f$ ) and the actinoid series (Period 7, thorium to lawrencium, filling $5f$ ), both conventionally shown as detached rows below the main grid.

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Q.The periodic table is divided into four blocks: $s$ , $p$ , $d$ and $f$ . State the rule used to assign an element to a block, and name the two series of elements that make up the $f$ -block.

Concept understanding — Structure of the Modern Periodic Table

Q.The periodic table is divided into four blocks: sss, ppp, ddd and fff. State the rule used to assign an element to a block, and name the two series of elements that make up the fff-block.

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Q.The periodic table is divided into four blocks: $s$ , $p$ , $d$ and $f$ . State the rule used to assign an element to a block, and name the two series of elements that make up the $f$ -block.

Unlock everything free for 14 days