(Hydrogen) A chemical element in the periodic table that has the atomic number 1. At standard temperature and pressure it is a colorless, odorless, nonmetallic, univalent, tasteless, highly More…
(Helium) A chemical element in the periodic table that has the atomic number 2. Helium is a colorless, odorless, tasteless, non-toxic, nearly inert monatomic chemical element that heads the More…
(Heating, Ventilation and Air-Conditioning) This is sometimes referred to as climate control. These three functions are closely interrelated, as they control the temperature and humidity of More…