Gas
(n.m.) One of the three states of matter. A gas occupies the entire volume available to it.
Generator
(n.m.) An element that transfers electrical energy to the rest of the circuit. The generator is the source of the electrical current flow.
Gold
(n.) Atom with atomic number Z equal to 79. It consists of 79 electrons orbiting a nucleus containing 79 protons and 118 neutrons. Symbol Au. Precious metal with a yellow and bright color. Gold is the most malleable and ductile of all metals. It can be reduced to sheets with a thickness of 1/1,000 of a mm. Its density is 19.3 kg/L. A good conductor of heat and electricity, it melts at 1063°C. Its boiling point is 2970°C. Unaffected by air, water, and acids, it is only soluble in a mixture of nitric acid and hydrochloric acid (aqua regia).
Graduated Cylinder
(n.) A graduated container used to precisely measure the volume of a liquid.
Graphical Representation
(n.) A curve in a coordinate system.
Gravitation
(n.f.) Attractive interaction between two objects possessing mass.
Greenhouse Effect
(n.) A natural phenomenon of planetary warming primarily due to water vapor, carbon dioxide, and methane present in the atmosphere.
Grid
(n.) A surface with fine lines used to decompose light.
Haze
(n.f.) (Old Provençal bruma, from Latin bruma, winter solstice) Light fog (horizontal visibility between 1 and 5 km).
Hertz, Heinrich Rudolph (1857-1894)
German physicist. Nobel Prize winner for his theory of luminescence.
Hertz
(n.m.) The legal unit of frequency, symbolized as Hz.
Heterogeneous
(adjective) Describes a mixture in which different liquids, solids, or gases can be distinguished with the naked eye or under a microscope.
Hexamethylenediamine
(n.m.) A colorless, harmful liquid. It is one of the reactants in the synthesis of nylon.
Homogeneous
(adjective) Describes a mixture in which only one liquid, solid, or gas is observed with the naked eye or under a microscope.
Hydraulic Power Plant
(n.) Plant that converts energy, generally accumulated by waterfalls at the foot of dams, into electrical energy.
Hydrochloric Acid
(n.) Colorless acidic solution with the formula (H+ + Cl-). It reacts with iron, zinc, and aluminum.
Hydrogen
(n.m.) An atom with an atomic number Z equal to 1. It is the smallest atom, consisting of one electron orbiting a nucleus that generally contains only one proton. Its symbol is H, and its model is represented as a white sphere.
Hypermetropia
(n.f.) A defect of the eye that results in blurry vision of nearby objects. It is corrected using a converging lens.
Hypermetropic
(adjective) Describes an eye that is not sufficiently convergent. Near vision is blurry.