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:
Answer:
I think B..
Explanation:
It is the sharing of electrons from one atom to another .
Answer:
Bromine (Br) loses an electron, so it is the reducing agent.
Explanation:
A reducing agent also called a reducer, is known to be an electron donor. A reducing agent is oxidized, because it loses electrons in the redox reaction.
A oxidising agent also called a oxidant or oxidiser, is known to be an electron acceptor. A oxidising agent is reduced, because it gains electrons in the redox reaction.
Cl2(aq) + 2Br-(aq) --> 2Cl-(aq) + Br2(aq)
Half ionic equations,
Cl2(aq) + 2e- --> 2Cl-(aq)
2Br-(aq) --> Br2(aq) + 2e-
Reducing agent = Br-
Oxidizing agent = Cl2
The balanced chemical reaction for this would be written as:
2Mg + O2 = 2MgO
We use this reaction and the amount of the reactant given to calculate for the amount of magnesium oxide that is produced. We do as follows:
1.5 g Mg (1 mol / 24.31 g) ( 2 mol MgO / 2 mol Mg ) (40.30 g /1 mol ) = 2.49 g MgO produced
The oxygen has 8 protons and 8 neutrons <span>in your nucleus
A = z + n
n = 18 - 8
n = 10 neutrons
Answer (3)
hope this helps!</span>
