Talk:Metalloid/GA1

GA Review

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Reviewer: Pyrotec (talk · contribs) 19:52, 26 July 2012 (UTC)[reply]

I will review. Pyrotec (talk) 19:52, 26 July 2012 (UTC)[reply]

Initial comments

I've done a couple of quick reads of the article. Overall, its certainly well referenced, so it should make GA by the end of this review.

I do think that one or two sections/subsections are a bit "weak", and that includes the WP:Lead - and I don't at this stage believe that the lead is compliant. However, that is all I'm doing tonight, I'll start the review proper tomorrow, starting at Definition. The lead will be done after I've got to the end of the article. Pyrotec (talk) 21:07, 27 July 2012 (UTC)[reply]

Definition

Looks OK.

Elements commonly recognized as metalloids -

I don't regard this sentence: Consistent with the list of metalloid lists, boron, silicon, germanium, arsenic, antimony and tellurium are commonly classified as metalloids.[4][5][19][20][21][22][n 3], as being particularly encyclopaedic. The article list of metalloid lists was created on 15 July 2011 and it is being claimed that books written in 1982, 2001, 1962, 1966, etc, are consistent with it. Well perhaps, but since neither wikipedia nor the article existed in 1962 the authors of that book could not have copied it. The rest of the paragraph makes further claims about some elements being sometimes in the list or sometime excluded. I believe that some elements may or may not be regarded as being metalloids, but whether or not they are listed in list of metalloid lists appears to be somewhat irrelevant - listing by wikipedia does not define them as metalloids.

Done Actually, list of metalloid lists lists various authors', both pre- and post-Wikipedia, lists of metalloids. The list is copied from the books and not the other way round. Nevertheless, the sentence doesn't seem good to me either, so I've removed "consistent with the list of metalloid lists". I've also removed the bolding for the individual elements, per MOS:BOLD. Double sharp (talk) 08:14, 6 August 2012 (UTC)[reply]

Thanks. A "nice and easy change", that I consider has improved the article. Pyrotec (talk) 18:27, 7 August 2012 (UTC)[reply]

- Boron -

Looks OK.

- Silicon -

Generally, OK. The first paragraph mentions that silicon is generally unreactive and is attacked by nitric acid and hot alkalis (well yes), but it does not mention attack by hydrofluoric acid and ignition when hot in chlorine and fluorine.

I can't now remember how I decided to treat these other forms of attack. I seem to recall the intended approach was to more or less address only the standard forms: air; acid (sulfuric; hydrochloric; nitric) and alkali since these were supposed to be summary bio's rather than duplications of main articles. I'll have another look at this re consistency. I see I've also referred to the attack of boron by fluorine, thereby contradicting myself. So, yes, need to go over this again.

Yes, boron has attack by fluorine and antimony has attack by aqua regia. As per my comment below, if the intention is to restrict the discussion to a limited range of "weathering agents", that needs to be stated at the start of the section. Pyrotec (talk) 18:32, 8 August 2012 (UTC)[reply]

Done I've clarified the susceptibility of silicon to various forms of attack. I haven't said anything about reactions at elevated temperatures (apart from e.g. exposure to hot acids) since a. probably most elements will react to something if heated enough, so where do you stop; b. the focus of the bio is supposed to be at ambient conditions; and c. other reactions are more properly the purview of the actual article for the element Sandbh (talk) 00:16, 11 August 2012 (UTC)[reply]

I'm undecided whether this should go here or later in Typical applications. There are a few "obvious" applications that aren't mentioned: silicon carbides, used as abrasives (e.g. carborundum, etc). SiO2 used as silica gel for moisture absorbing, "natural SiO2" in the form of china clay, clay/mud, etc, used for bricks, tiles, pottery; and silicones (used in oils, polymers, etc).

I believe the intention was to only list the uses shared by all of the recognized metalloids, rather their individual-specific uses, as covered in their main articles.

The article could be written in that way, but the wording currently used is: This section includes brief sketches of the physical and chemical properties of the applicable elements. For complete profiles, including occurrence, production, history, biological role and precautions, see the main article for each element. The wording would need to reflect such a decision. Pyrotec (talk) 18:32, 8 August 2012 (UTC)[reply]

Done I've tuned the introductory note to this section in order to (hopefully) better define its scope Sandbh (talk) 11:42, 10 August 2012 (UTC)[reply]

- Germanium -

Looks OK.

- Arsenic , Antimony & Tellurium-

The Arsenic subsection starts off boldly: "Arsenic is a grey, metallic looking solid.". Well the grey allotrope is, but the main article lists two other forms and they are not grey, metallic looking solids. So, it aught to be made clear that this discussion is about the "common" grey form of arsenic.

I'll see if I can make it clearer that the article is about the applicable elements in their most thermodynamically stable forms at room temp, unless indicated otherwise.

Done Hopefully fixed via another qualifying edit to the introductory note to this particular section Sandbh (talk) 12:22, 10 August 2012 (UTC)[reply]

Antimony also has its allotropes, but they are less stable, so perhaps a clarifying comment is unnecessary.

Done As per above Sandbh (talk) 12:22, 10 August 2012 (UTC)[reply]

Otherwise, all three subsections are OK.

- Typical applications -

See comments above in Silicon.

.... Stopping at this point. To be continued. Pyrotec (talk) 20:50, 7 August 2012 (UTC)[reply]

Thank you very much for doing this GA review. Sandbh (talk) 09:00, 8 August 2012 (UTC)[reply]

Thanks. I would expect this article to make GA by the end of the review, these a just "minor problems" that need to be sorted out first. Pyrotec (talk) 18:48, 8 August 2012 (UTC)[reply]

In general, I have no problems with this subsection. However, I would have been tempted to suggest the borax article as source of additional information on other uses of boron which don't appear here; but that will be dependant on resolving the comments raised in Silicon, above. Pyrotec (talk) 18:48, 8 August 2012 (UTC)[reply]

Done As per edit (for silicon) to the introductory note to this particular section Sandbh (talk) 12:22, 10 August 2012 (UTC)[reply]

Elements less commonly recognized as metalloids -
- Untitled subsection -

Looks OK.

- Carbon -

I found the claim: It can form ionic salts, including a sulphate, perchlorate, nitrate, hydrogen selenate, and hydrogen phosphate.[228] some what surprising, but ref 228 did give an example of the formation of C⁺₂₄H₂SO₄^-.2.4H₂SO₄ and states that other salts can be formed. They are, according to the source, rapidly attacked by water and by moisture in the air. However, I do not think that the statement can stand as it is without further explanation. The method of preparation is (careful) direct oxidation of graphite in concentrated sulphuric acid by oxidising agent, so the concentrated sulphuric acid is acting as an Inorganic nonaqueous solvent.

Done I've incorporated your good prose into a note. Sandbh (talk) 11:07, 15 August 2012 (UTC)[reply]

- Aluminium -

It states: Its oxide is amphoteric, and a conditional glass-former.[62], well the reference only confirms that it is a glass-former. Aluminium oxide is quite unreactive, its certainly less chemically reactive than the metal and it has a higher melting point. I'd suggest that Aluminium, itself, is amphoteric as it forms aluminates (and that is stated in Other metalloids).

Done I've added a reference re the amphoterism of the oxide. I steered away from mentioning the amphoterism of actual elements, as opposed to their oxides, in order to avoid confusion with the other concept of metalloids as amphoteric metals, such as vanadium, chromium, molybdenum, tungsten, and lead. Sandbh (talk) 11:07, 15 August 2012 (UTC)[reply]

- Selenium & Polonium -

Both subsections look OK.

- Other metalloids, Near metalloids & Allotropes -

This three subsections look OK.

Categorization and periodic table territory -

Looks OK.

Comparison of properties with those of metals and nonmetals -

Looks OK.

Quantitative description & Nomenclature and history -

These two sections look OK.

WP:Lead -

This is intended to both introduce the topic and summarise the main points (see WP:Lead. For an article of this length, this lead is rather "thin", but three (or four) paragraphs is an adequate number. The lead is also required to proportionately cover all the points in the article; and the section that appears to be entirely absent is Elements less commonly recognized as metalloids, which forms perhaps a third to a quarter of the article (excluding the notes and citations).

At this point, I'm putting the review On hold, the article is substantially compliant apart the lead which needs to be brought up to standard. Pyrotec (talk)

Done Thank you Pyrotec. I've added a paragraph summarizing the nub of the Elements less commonly recognized as metalloids section. It borrows some of the periodic table territory part of the following section, since the two notions are closely related. Sandbh (talk) 11:35, 16 August 2012 (UTC)[reply]

Thanks. 18:31, 16 August 2012 (UTC)

Overall summary

GA review – see WP:WIAGA for criteria

An informative and well referenced article

Is it reasonably well written?
A. Prose quality:

B. MoS compliance for lead, layout, words to watch, fiction, and lists:
Is it factually accurate and verifiable?
A. References to sources:

B. Citation of reliable sources where necessary:

C. No original research:
Is it broad in its coverage?
A. Major aspects:

B. Focused:
Is it neutral?
Fair representation without bias:
Is it stable?
No edit wars, etc:
Does it contain images to illustrate the topic?
A. Images are tagged with their copyright status, and valid fair use rationales are provided for non-free content:

B. Images are provided where possible and appropriate, with suitable captions:
Overall:
Pass or Fail:

I'm happy to award this article GA-status. Thanks for responding quickly and positively to my comments above. Pyrotec (talk) 18:31, 16 August 2012 (UTC)[reply]