Students should be able to: draw dot and cross diagrams for the molecules of hydrogen,chlorine, oxygen, nitrogen, hydrogen chloride, water, ammonia and methane.........When I saw this, my first thought was that students taking this exam should really score on questions on drawing dot and cross diagrams of molecules (note, under ionic compounds, this syllabus include other compounds which dot and cross diagram students need to know). The syllabus has specifically mentioned drawing these eight covalent molecules. Just practice drawing these many times, and you will score on this question.
Well, I have previously wrote a few blog posts detailing how to draw the dot- and- cross diagrams. You can find them here:
- Drawing dot and cross diagrams (showing all electrons)
- Drawing dot and cross diagrams (showing outermost electrons)
For the O level syllabus that Singapore students sit for, please note that you are not only restricted to drawing these eight molecules.
I have created two videos on drawing the dot and cross diagrams for these eight molecules, namely hydrogen,chlorine, oxygen, nitrogen, hydrogen chloride, water, ammonia and methane. One video shows the dot and cross diagrams with the outermost electrons only and another shows all the electrons.
Related Posts- Chemical bonding- Determine electronic configuration
- Drawing dot and cross diagrams (showing all electrons)
- Drawing dot and cross diagrams (showing outermost electrons)- Formulae of ionic compounds- Formulae of covalent molecules
- Ionic compounds and moleculesRelated Google App
- Find number of electrons - Notes and Quiz
- Find electronic configuration - Notes and Examples
Questions:
- Quizzes and Tests on Chemical Bonding
