Answer: Although the best-known cause of a mass extinction is the asteroid impact that killed off the non-avian dinosaurs, in fact, volcanic activity seems to have wreaked much more havoc on Earth's biota. Volcanic activity is implicated in at least four mass extinctions, while an asteroid is a suspect in just one. Examples, of mass extinctions are Permian extinction of marine species, and Cretaceous extinction of various species, including dinosaurs.
Answer:

Explanation:
The half-cell reduction potentials are
Ag⁺(aq) + e⁻ ⇌ Ag(s) E° = 0.7996 V
Fe²⁺(aq) + 2e⁻ ⇌ Fe(s) E° = -0.447 V
To create a spontaneous voltaic cell, we reverse the half-reaction with the more negative half-cell potential.
The anode is the electrode at which oxidation occurs.
The equation for the oxidation half-reaction is

Answer:
gas are well separated with no regular arrangement. liquid are close together with no regular arrangement. solid are tightly packed, usually in a regular pattern.
Explanation:
<h2>Answer : Option B) The hematite particles rearrange to form a new substance.</h2><h3>Explanation :</h3>
Hematite particles when gets rearranged to form a new substance, is an example of a chemical change.
As a chemical changes is usually a change where a substance undergoes a chemical change and forms a new substance; which cannot be easily reversed into reactants by any simple physical methods.
In this example the hematite ore forms a new substance by an irreversible chemical change.
4p, 3d, 3p, 3s, 2p, 2s and 1s orbitals may be occupied during de-excitation.<span />