ELEMENTS
Jonathan Rawle, January 1996



Instructions
------------

Clicking on the iconbar icon with the select button opens a window
containing the chemical elements in the familiar periodic table arrangement.
Clicking on an element with adjust will display the usual information about
that element (atomic number, symbol, name and relative atomic mass).
Clicking on an element with select opens a larger window containing element
data:

 Atomic number, name, symbol, relative atomic mass
 Atomic radius in picometres (pm)
 First ionisation energy (the energy needed to remove the outermost
  electron from each of 1 mole of atoms is their gaseous state) in
  kilojoules per mole (kJ mol)
 Electronegativity (in Pauling's units)
 Principle oxidation numbers, and the corresponding ionic radii in
  picometres (pm). (Some elements have only 1 oxidation state)
 Density in kilograms per cubic metre (kg m) or grams per cubic
  centimetre (g cm) - see 'changing the units' below 
 Specific heat capacity in Joules per kilogram per kelvin (J kg K) or
  Joules per gram per Kelvin (J g K) (see below). It should be noted
  that  1 J kg K =  1 J/kgC
 The melting and boiling point in any of the 5 temperature scales (see
  'changing the units') and the state at room temperature (25C). Subl
  denotes that the element sublimes (passes straight from solid to gaseous 
  state).
 The crystal structure of the element in its usual solid state  
 How the element's name was derived, the date and country of discovery, and   who discovered it

For some elements, data is unknown or unobtainable. In these cases a '-' is 
displayed in the place of a number.

Some elements also have text and/or draw files associated with them, and
these can be accessed by clicking on the text and draw file icons
respectively. You may want to edit these files. If so, read the file 'Adding'
which is inside the !Elements application directory.
There are also icons labelled 'last element' and 'next element'. These take 
you to the previous and next atomic numbers.

Clicking the menu button over the element data window allows you to type in
an element name, symbol or atomic number, and the data for that element will
then be displayed. (Only the first few letters of the name need be entered,
and the program will attempt to match it with an element name.)

The data window can also be opened at any time by clicking with adjust
(right hand button) on the iconbar icon.

                                      ***

Clicking menu over the periodic table displays a menu containing various
options. The first group of these allow different types of information to be
displayed on the periodic table. For example, selecting 'metals' updates the
periodic table to show which elements are metallic. 
For the 'state' and 'year' options, there is a dialogue box, into which you
can type a value. Arrows appear on the periodic table, and also allow you to
change this value.

Selecting 'group numbers' and 'period numbers' displays these pieces of
information on the periodic table.

The option 'save status' saves every option on this menu to disc, so that
these options will be selected automatically when the program is started.


Iconbar menu
------------

Clicking menu over the iconbar icon displays another menu. From here, you
can open windows that allow you to:

 Calculate the molecular mass of a compound:
   Enter the molecular formula in its usual form (there are no subscript 
   numbers, so use ordinary numbers, for example Ca3(PO4)2 for calcium
   phosphate).
 Find the estimated amount of ionic character of a bond
 Display information about the different temperature scales
 Test your knowledge of element symbols and atomic numbers
 Change the units used in the program (see below)

It also contains the usual program info, and the 'quit' option.


Changing the units
------------------

The Units window, accessed through the iconbar menu, allows you to change the
units in which certain quantities are expressed (temperature, density and
specific heat capacity). Clicking on OK, instructs the program to use the
units selected in the window, and immediately updates all displays.
Clicking on Save also saves these units as the defaults to be used next time
the program is started.
