The period of time required for the disintegration of half of the atoms in a sample of a specific radioactive substance. Half Round Molding which resembles a cylinder cut in half. Half Round File File with one flat side and one side a curved half-section, lengthwise of a cylinder. Half Section View of a section of an object that is taken halfway through with the other half depicted from the exterior, showing the object with half cut away, showing the inside. Half-timber Construction style that leaves large boards exposed on the outside walls with the wall surface between them covered with stucco or another similar material.
Chlorine is used as a bleach and disinfectant.
Bromine is used in dyes and for flame-proofing. The Fluorocarbon form of fluorine is used as a lubricant, refrigerant and in fire extinguishers. Hammer A tool for pounding which is a metal head fastened across one end of a hand with one end of the head may be a pronged claw for pulling nails, as in a carpenter's handle. Hammer Fracture Overdriving a nail to cause a tear in the gypsum wallboard paper. Hand Drill Drill, which is manually driven by a turning crank that rotates the drill bit faster than the crank, turns.