2.18—Explain: i the trends in melting and boiling temperatures of the elements of Periods 2 and 3 of the Periodic Table in terms

Be able to explain: i the trends in melting and boiling temperatures of the elements of Periods 2 and 3 of the Periodic Table in terms of the structure of the element and the bonding between its atoms or molecules ii the general increase and the specific trends in ionisation energy of the elements across Periods 2 and 3 of the Periodic Table iii the decrease in first ionisation energy down a group.

Use —explain: i the trends in melting and boiling temperatures of the elements of periods 2 and 3 of the periodic table in terms to connect the rule to the data and decision in the question.

This matters because —explain: i the trends in melting and boiling temperatures of the elements of periods 2 and 3 of the periodic table in terms determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —explain: i the trends in melting and boiling temperatures of the elements of periods 2 and 3 of the periodic table in terms to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Explain: i the trends in melting and boiling temperatures of the elements of Periods 2 and 3 of the Periodic Table in terms is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.