Genetic engineering, recombinant DNA technology, genetic modification/manipulation (GM) and gene splicing are terms that apply to the direct manipulation of an organism's genes. ... Genetic engineering uses the techniques of molecular cloning and transformation to alter the structure and characteristics of genes directly.
The answer is: when the aim is to show electron distributions in shells
An orbital notation is more appropriate if you want to show how the electrons of an atom are distributed in each subshell. This is because there are some atoms that have special electronic configurations that aren't obvious in just written configurations.
Break down the table into smaller sections. Memories period by period or if you like by group (like halogens or noble gases). Just say the elements in order everyday 1-10 then when you get those 11-20 and continued.
