The resistance of a circuit is a measure of the energy
that a current loses while flowing through the circuit.
Ease or difficulty is not a helpful concept in the case of
an electrical circuit.
Answer:
A. Mass-extinction events are times in the Earth's history when few species evolve.
Explanation:
The extinction that occurred 65 million years ago wiped out some 50 percent of plants and animals. The event is so striking that it signals a major turning point in Earth's history, marking the end of the geologic period known as the Cretaceous and the beginning of the Tertiary period.
A wide range of animals and plants suddenly died out, from tiny marine organisms to large dinosaurs.
Species go extinct all the time. Scientists estimate that at least 99.9 percent of all species of plants and animals that ever lived are now extinct.
From the solubility rules, both reactions 1 and 2 lead to precipitates.
<h3>What is a precipitate?</h3>
The term precipitate refers to the solid that separates out of the reaction mixture . We know that the solubility of a substance in water is predicated on the solubility rules.
1) The reaction here is;
Fe(NO3)3(aq) + 3NaOH(aq) ------> Fe(OH)3(s) + 3NaNO3(aq) - The precipitate is Fe(OH)3 because only the hydroxides of group 1 elements are soluble in water.
2) The reaction is;
Pb(NO3)2(aq) + 2KI(aq) ----->PbI2(s) + 2NaNO3(aq) - The precipitate is PbI2 because most iodides are soluble except the iodides of Ag+, Hg+2, and Pb+2
Complete Ionic equation;
Pb^2+(aq) + 2NO3^-(aq) + 2K^+(aq) + 2I^-(aq) ------> PbI2(s) + 2NO3^-(aq) + 2K^+(aq)
Net ionic equation;
Pb^2+(aq) + 2I^-(aq) ------> PbI2(s)
Learn more about the solubility rules:brainly.com/question/12978582
##SPJ1
<span>If the entropy is greater than the enthalpy, it will have more spontinaity</span>
C → A → E → D → F → H → G → I → B
Explanation:
Put into the proper order, the following are the stages of star formation from earliest to latest:
Massive, rotating, amorphous interstellar cloud collapses and fragments → Infalling material forms a hot and luminous protostar at the center of the disk → Gravitational contraction causes protostar to shrink and heat as it descends the Hyashi track → As the shrinking protostar heats up, hydrogen is ionized and a magnetic field forms → Magnetic bipolar outflows begin along rotation axis as the magnetic field forms → As bipolar outflows become stronger, powerful T-Tauri winds start clearing the nebula before the onset of nuclear fusion → Shrinking cloud collapses into a flat disk shape → Onset of nuclear fusion in the core occurs around 15 million K → Newly-formed star settles onto the Main Sequence
