How a configuration places an element in the table, what isoelectronic means for size, and every periodic trend with the exceptions the paper actually asks about.
Unit 1 carries 17 of the 50 chemistry marks; with fourteen chapters sharing them, this one averages a little over one (MEC publishes weights by unit, not by chapter). Like Atomic structure it earns more than its share, because a trend question can be set about any element in the table and because the same trends explain half of Chemistry of non-metals and Chemistry of metals.
The MEC scope line runs: Modern periodic law and table; s, p, d and f block elements; isoelectronic species; periodic trends: atomic size, ionic size, ionisation potential, electronegativity, electron affinity, metallic character. The headings below are its points, in MEC's order.
Three ways it comes: recall (which block an element sits in, how many elements in period 4, the most electronegative element); understanding (why nitrogen's ionisation energy beats oxygen's, why chlorine's electron affinity beats fluorine's); application (arrange four ions of an isoelectronic set by size, or place an element from a given configuration).
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