Dark energy and dark matter seem over analyzed, although they are no different than gravity and wind. Dark energy can be the pulling caused by black holes, stars, and large planets. Dark matter also is just the effect of cosmic dust and debris pushed from explosions but also pulling caused by distant gravitational bodies.
Answer:
Whether barium chloride solution was pure
Explanation:
We may answer whether barium chloride was pure. The sequence of this experiment might be depicted by the following balanced chemical equations:
Having a total sample of 10.0 grams, we would firstly find the mass percentage of barium in barium chloride:
This means in 10.0 g, we have a total of:
of barium cations.
The precipitate is then formed and we measure its mass. Having its mass determined, we'll firstly find the percentage of barium in barium sulfate using the same approach:
Multiplying the mass we obtained by the fraction of barium will yield mass of barium in barium sulfate. Then:
- if this number is equal to 6.595 g, we have a pure sample of barium chloride;
- if this number is lower than 6.595 g, this means we have an impure sample of barium chloride, as we were only able to precipitate a fraction of 6.595 g.
MH₂ = 2×mH = 2×1g = 2 g/mol
Answer:
The tectonic style and viability of modern plate tectonics in the early Earth is still debated. Field observations and theoretical arguments both in favor and against the uniformitarian view of plate tectonics back until the Archean continue to accumulate. Here, we present the first numerical modeling results that address for a hotter Earth the viability of subduction, one of the main requirements for plate tectonics. A hotter mantle has mainly two effects: 1) viscosity is lower, and 2) more melt is produced, which in a plate tectonic setting will lead to a thicker oceanic crust and harzburgite layer. Although compositional buoyancy resulting from these thick crust and harzburgite might be a serious limitation for subduction initiation, our modeling results show that eclogitization significantly relaxes this limitation for a developed, ongoing subduction process. Furthermore, the lower viscosity leads to more frequent slab breakoff, and sometimes to crustal separation from the mantle lithosphere. Unlike earlier propositions, not compositional buoyancy considerations, but this lithospheric weakness could be the principle limitation to the viability of plate tectonics in a hotter Earth. These results suggest a new explanation for the absence of ultrahigh-pressure metamorphism (UHPM) and blueschists in most of the Precambrian: early slabs were not too buoyant, but too weak to provide a mechanism for UHPM and exhumation.
Explanation:
