Period 1 element lithium and fluorine (appearing twice), or left floating above the other elements and not assigned to any group in the periodic table. Helium is almost always placed above neon (which is in the p-block) in the periodic table as a noble gas, although it is occasionally placed above beryllium due to their similar electron configuration. Hydrogen (H) is the chemical element with atomic number 1. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H. With an atomic mass of 1.00794 amu, hydrogen is the lightest element. Hydrogen is
Solid ground floor mm to 225 mm. Though due to poor workmanship and dust this type of floor finish fails through lifting. Terrazo: Terrazo consists of a coloured element binder or matrix and marble chips mixed to specified proportions. The finish is hardwearing, attractive and resistant to chemical attack. Ebonite strips divide the terrazo into bays to avoid shrinkage and expansion. Solid ground floor A solid ground floor consists of a layer of concrete, which in the case of a domestic building will be the surface layer brought up to ground floor level with hardcore filling under it. The advantage of a solid