Un recipiente para gases contiene 2 moles del compuesto gaseoso óxido de dinitrógeno (N2). Este óxido, sometido a ciertas condiciones, se descompone
totalmente en los gases que indica la ecuación
N2O(g)  2N2(g) + O2(g)
Al término de esa descomposición habrá sucedido que:

I. la masa habrá aumentado
II. el número de moles no se habrá modificado
III. el número de moles habrá aumentado
IV. la masa no habrá cambiado

The earth's moon is unusually large. two popular theories of the moon's origin include the "sister world" hypothesis, which states that the moon formed from the same materials as the earth, near enough to the earth that they fell into orbit around each other. a second theory is the "capture" hypothesis, in which the moon formed elsewhere in the solar system, and the earth's gravity pulled it into its orbit. studies of what the moon is made of indicate that some of its materials had to come from the earth or from the same area of the solar system where the earth had formed. at the same time, the moon does not contain much of the material that makes up the earth's core, so the moon could not have formed from the same materials as the earth. how do the two facts above affect the described theories of the moon's origin? a. they show that scientists will never agree on where the moon came from. b. they show that more experiments on moon formation need to be done. c. they show that no theory accounts for the existence of the moon. d. they show that neither theory is complete and entirely correct.

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.

Which factor is likely to impact the possible number of compounds? presence of unlimited number of elements in the periodic table the inability of atoms to align perfectly with other atoms the ability of all elements to react with every other element all elements being equally reactive