Reacciones y Cambios Reacciones Químicas (versión previa) por Anthony Carpi, Ph.D. Lectura Prueba Teach with this What kind of elements in the periodic table did William Ramsay discover? metalloids metals noble gases nonmetals The inertness of noble gases means that they: exist as gases at room temperature lose and gain electrons easily tend not to react with other elements tend to undergo many chemical reactions Noble gases are inert due to: their special number of neutrons and protons their number of electrons in the outermost shell the form of their nuclei their bonding with other elements In chemical reactions, when atoms gain or lose electrons they form: ions neutrons new atoms noble gases The number of valence electrons in the group A elements is determined by: atomic number group number period number rank of the element What type of elements lose electrons when they enter into chemical reactions? metals noble gases nonmetals none of the choices What type of elements gain electrons when they enter into chemical reactions? metals noble gases nonmetals none of the choices What is the maximum number of electrons that helium can have? Eight Four Three Two Under what category of elements does helium fall: metals metalloids noble gases nonmetals What is an exothermic chemical reaction? a reaction that absorbs energy a reaction that releases energy a spontaneous reaction none of the choices What is an endothermic chemical reaction? a reaction that absorbs energy a reaction that releases energy a spontaneous reaction none of the choices What reaction happens immediately after two substances are mixed? endothermic exothermic spontaneous none of the choices What kind of change accompanies any chemical reaction? change of time change of order of elements change of nuclei change of energy Resultados de Prueba