Answer: Hard
Explanation:
The upper part of the mantle is hard as it contains thick rock layers. The mantle's upper layer and the crust make up a brittle and rigid rock that's referred to as the Lithosphere.
The upper mantle starts below the Earth crust and then stops at the start of the lower mantle. We should note that the upper mantle results in the movement of the tectonic plates.
Answer:
D: Electron - Negative Charge
Explanation:
Protons have a positive charge, (pro = +)
Neutrons have a negative charge, (neutral = 0
Electrons have a negative charge.
An element is determent by the number of protons in the atom, the Isotope of an element is determined by the number of neutrons, and the charge of an atom is determined by its electrons, which is equal to the number of protons.
Half life of the reaction is :-101.9 min
a→b
25% reacted means 75% remains
t=42 min
Rate constant
k=(2.303/t)(log a/a-x)
k=(2.303/42)(log 100/100-25 )
k=(0.054) (log 100/75)
k=(0.054)(0.1249)
k=0.0068per min
half life
t1/2=(0.693/k)
=(0.693/0.0068)
=101.9 min
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