A soft keyboard (sometimes called an onscreen keyboard or software keyboard) is a system that replaces the hardware keyboard on a computing device with an on-screen image map.
An ideal gas is defined as one in which all collisions between atoms or molecules are perfectly eleastic and in which there are no intermolecular attractive forces. One can visualize it as a collection of perfectly hard spheres which collide but which otherwise do not interact with each other.
The Ideal Gas Law is one of the Equations of State. Although the law describes the behavior of an ideal gas, the equation is applicable to real gases under many conditions, so it is a useful equation to learn to use. The Ideal Gas Law may be expressed as: PV = NkT.