Natasha Huma
Atoms
There are 112 elements although elements 110-112 are as yet unnamed. These 112 elements are organized in the periodic table:
The modern chemical symbols were introduced by Berzelius. Rows of elements are called "periods" and columns of elements are called "groups" (1A, 2A 3B etc.). There are three general classes of elements distinguished by their physical properties: the metals (generally shiny and conduct electricity), the non metals (not shiny, sometimes gasses at STP and poor conductors of electricity) and the metalloids (properties in between those of metals and non metals.). Some groups have special names:
Many of the heavier elements are unstable - which means that the atoms of those elements break apart very quickly.
Elements within a group share similar chemical properties. Other chemical and physical properties of the elements can be deduced from their position in the periodic table. The structure of the periodic table and thus their chemical and physical properties is directly related to their atomic structure.
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Peer Reviews
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Quality of writing
The candidate’s quality of writing is extremely good – sentences and paragraphs are constructed well allowing effective conveyance of meaning. Terms are defined precisely and succinctly lending a lean flow to the piece. One thing though, the paragraph on sub-atomic particles is repeated at the end of the piece – it does not elaborate on anything and so should be deleted. Overall the piece is very good – an accurate informative description of the atom is given, with a look at different properties and aspects of the atom.
Level of analysis
Most points have been made in the above section due to this being a piece that does not require a large amount of analysis. One thing that I would say however is that there should be a conclusion for a piece such as this – the candidate could talk about how this knowledge of the atom is applied in modern chemistry, however the topic is broad enough that a look specifically at just the atom in itself still works well.
Response to question
There is not so much a posed question for this piece as more an instruction to discuss and inform about the nature of the atom, which the candidate does very well. The piece includes a good look at the history of the atom and its fundamentals which is essential to understanding the atom and, by extension, chemistry. One thing that could be done better is to give examples of chemical properties, such as reactivity to illustrate the nature of the periodic table to have atoms with similar chemical properties situated together. An example of this could be the high activity of the group 1 alkali metals. The explanation of isotopes is good, however the section about sub-atomic particles should come before this to allow the candidate to elaborate more about protons.