3 CHEMICAL SIGNS AND SYMBOLS

3.1    Chemical Arrows. The braille representation of arrows listed below must be used in place of the ones listed in the Nemeth Code. All other arrows must be transcribed as required by the Nemeth Code.

Up-pointing Regular		$<
Boldface		$_<
Down-pointing Regular		$%
Boldface		$_%
Bold up-pointing followed by regular down-pointing		$_<"%
Regular up-pointing followed by bold down-pointing		$<"_%
Regular up-pointing followed by regular down-pointing		$<"%
Vertical or oblique dipole Up-pointing		$+<
Down-pointing		$+%
Half-barb up-pointing followed by half barb down-pointing		$@<",%
Horizontal Dipole, right-pointing		$+3o
Dipole, left-pointing		$[3#
Crossed arrow		/$[3o

3.2.1 Electron Dots

Single regular	.	*
Single bold or hollow		/
Small x	x	x
Pair, regular	:  ¨	?
Pair, hollow or bold		#
Pair, x's		[
Pair, right or upper bold or hollow, left or lower regular		]
Pair, right or upper x, left or lower regular		%
Pair, right or upper regular, left or lower bold or hollow		&
Pair, right or upper regular, left or lower x		$
Pair, right or upper bold or hollow, left or lower x		:
Pair, right or upper x, left or lower bold or hollow		>
Triplet (three pairs of regular electron dots)	=  or	\
Other triplets Insert dots 46 before a pair shown horizontally in the list above to indicate that the arrangement is a triplet. For example:		.%

3.2.2  Horizontal (including indicators)

Single		_3]
Double		_7]
Triple		_=]
Arrow, right-pointing		_3o]
Arrow, left-pointing		_[3]
Barred		_\]
Bold		_g]
Broken		_2]
Dotted		_1]
Jagged, single		_e]
Jagged, double		_ei]
Wavy, single		_9]
Wavy, double		_95]

3.2.3 Oblique

Lower left to upper right		_/
Lower left to upper right, double		_//
Upper left to lower right		_*
Upper left to lower right, double		_**
Arrow, lower left to upper right		_/<
Arrow, lower right to upper left		_*<
Arrow,, upper left to lower right		_*%
Arrow, upper right to lower left		_/%
Broken, lower left to upper right		_2/
Broken, upper left to lower right		_2*
Dotted, lower left to upper right		_1/
Dotted, upper left to lower right		_1*
Barred, lower left to upper right		_x/
Barred, upper left to lower right		_x*

Bonds, cont.

3.2.4 Vertical

Single	|	_
Double	||	__
Triple	|||	___
Arrow, up-pointing		_<
Arrow, down-pointing		_%
Barred		_x
Bold		_g
Broken		_2
Dotted		_1
Jagged, single		_e
Jagged, double		_ei
Wavy, single		_9
Wavy, double		_95



3.2.5 Wedges, Vertical or Oblique

Down-pointing, normal outline		_m
Up-pointing, normal outline		_u
Down-pointing, filled in		_p
Up-pointing, filled in		_v
Down-pointing, dotted outline		_1m
Up-pointing, dotted outline		_1u
Down-pointing, dashed outline		_2m
Up-pointing, dashed outline		_2u
Down-pointing, barred		_xm
Up-pointing, barred		_xu



3.2.6 Wedges, Horizontal (including indicators)

Right-pointing, normal outline		_o]
Left-pointing, normal outline		_[]
Right-pointing, filled in		_r]
Left-pointing, filled in		_w]
Right-pointing, dotted outline		_1o]
Left-pointing, dotted outline		_1[]
Right-pointing, dashed outline		_2o]
Left-pointing, dashed outline		_2[]
Right-pointing, barred		_|o]
Left-pointing, barred		_|[]



3.3 Ring Structures

Vertices (this two-celled symbol represents
any unlabeled vertex)

                 [o



Circle (broken outline)
                                                                                  $bc


Hexagon (broken outline)
                                                                                  $b6



3.4 Miscellaneous Symbols and Indicators

3.4.1 Chemical Period


3.4.2 Modifiers. These symbols are to be used as spatial modifiers only. In linear expressions, the full construct of the Nemeth Code must be used. (See Examples 5.3.1-9 and 7.2-3.)






Crossed O		@.o
Plus sign within a circle		$c+
Minus sign within a circle		$c-


3.4.3 Lines (partitions, not bonds)

Broken vertical		.|
Dotted vertical		@|
Dotted, double vertical		@|@|
Jagged, vertical		@@|
Jagged, horizontal		"5959



3.4.4 Modified-Letter Indicators

Small capital* @",

Barred capital @;|,

Example 3.4.4-1: (small capital D) D

@",d

Example 3.4.4-2: (barred capital R)

@;|,r

*Assuming the small capital letter is on the same level as normal letters.

3.5   Symbols for the Chemical Elements. The Nemeth Code defines "sign" as the printed mark and "symbol" as the braille representation of that sign. The usual nomenclature for the letter(s) representing the name of a chemical element is "chemical symbol." In this Chemistry Code, the word "SYMBOL" (all upper case) is used to denote the letter(s) representing a chemical element and "symbol" (lower case) to denote the meaning as given in the Nemeth Code. A SYMBOL for a chemical element consists of a single capitalized letter or a capitalized letter followed by one or more lower case letters. These SYMBOLS are not abbreviations as defined by the Nemeth Code, (i.e., Nemeth Code Rule VIII does not apply to SYMBOLS).

** CAUTION ** In print, sanserif type form is often employed in tables and diagrams. In this case, the capital I (eye) and the lower case l (ell) are easily confused. Upon careful examination it is usually possible to distinguish between them as the I is usually thicker than the l. Be aware of this and be sure to discriminate.





3.5.1 Capitalization. When SYMBOLS appear in a series, as in a molecule, each SYMBOL must be capitalized individually.



3.5.2 Spacing. Follow the print spacing.

Example 3.5.2-1: CH

,c,h

Example 3.5.2-2: MgO

,mg,o

Example 3.5.2-3: H--O--H

,h_3],o_3],h




3.5.3 Punctuation. Chemical SYMBOLS must be punctuated in the mathematical mode as defined in Nemeth Code Rule VI.


Example 3.5.3-1: Water is HOH.

,wat] is ,h,o,h_4