The standard enthalpy of formation. The enthalpy of formation is the energy change when 1 mole of a substance is formed from its constituent elements in their standard states.Particular points to note: 1  The elements are in their usual states under standard conditions. i.e at 25ÂºC and 1 atmosphere pressure (100 kPa).he standard enthalpy of formation. The enthalpy of formation is the energy change when 1 mole of a substance is formed from its constituent elements in their standard states.
Microsoft bumped the layout to 104 keys with the addition of Windows keys and a Menu key a bit later, but the layout is essentially the same. This is a rule-of-thumb, as no two keyboards are exactly the same. The number of keys on a full size keyboard varies, some having media keys, etc.
Closeup photo of a 101-key Enhanced keyboard, showing the layout of the various. key groups. Contrast this layout to that of the 104-key Windows keyboard. The Enhanced keyboard was electrically the same as the 84-key AT keyboard, but featured a radically redesigned key layout. 1  The major changes included these: 2  Dedicated Cursor and Navigation Keys: Finally, separate keys were provided for cursor control and navigation.