Practise IB Chemistry HL 3.1.1 by analysing periodic-table organization and connecting position to chemical character and trends.
Lithium and boron are elements in period 2 of the periodic table. Lithium occurs in group 1 (the alkali metals) and boron occurs in group 3. Isotopes exist for both elements.
Distinguish between the terms group and period.
Group: (elements in vertical) columns in periodic table and Period: (elements in horizontal) rows in periodic table; Allow elements in same group have similar chemical properties and within a period, atoms have same number of shells/energy levels (but number of electrons in valence/outer shell increases).
Marking guidance:
Allow groups distributed vertically and periods distributed horizontally / OWTTE.
Allow group number gives number of valence/outer shell electrons (for main
group elements) and period gives same number of shells/energy levels.