Answer: D) The amount of air in a room never changes.
Explanation: Equilibrium is defined as the state in which the concentration of reactants and products is constant or the rate of forward direction is equal to the rate of backward direction.
a) The percentage of nitrogen gas in a room decreases steadily: the amount decreases that means the reaction is taking place in one direction and hence the reaction is not in equilibrium.
b) A blade of grass grows taller : the plant gets taller that means the reaction is taking place in one direction and hence the reaction is not in equilibrium.
c) The amount of water in a cup decreases as it evaporates: The amount of water is decreasing that means the reaction is taking place in one direction and hence the reaction is not in equilibrium.
d) The amount of air in a room never changes: the amount of air does not change as the amount of air leaving the room is same as that of the air entering the room and hence the reaction is in equilibrium.
Answer:
They found evidence of an impact crater in Mexico
Explanation:
The K-Pg boundary is the boundary between the Cretaceous period and the Paleogene period, but also marking the end of the Mesozoic era and the beginning of the Cenozoic era. This boundary is dated to roughly 66 million years ago. The K-Pg boundary is characterized with a mass extinction. The dominant organisms on Earth all died out, including the dinosaurs, both terrestrial and aquatic, as well as the flying reptilians, with only the birds surviving from that super-family. The reason for the mass extinction has been an impact with an asteroid or a comet, that was very large and hit the Earth where the Yucatan Peninsula in modern day Mexico is located. The impact was devastating, with heat waves, tsunamis, earthquakes, triggering of the majority of the volcanoes, wildfires, all combined managed to devastate the environment, thus big portion of the species living in it as well. The lucky survivors were smaller organisms, and the mammals turned out to be the most successful in occupying the empty niches and have became the dominant organisms on the planet.
It should be 50% and 25%.
