Answer:
The half-life (t1/2) is the time taken for the activity of a given amount of a radioactive substance to decay to half of its initial value. The mean lifetime (τ, “tau”) is the average lifetime of a radioactive particle before decay. The decay constant (λ, “lambda”) is the inverse of the mean lifetime
For the answer to the question above, oxygen makes it Redi would think it has to do with the amount of oxygen in the blood stream. So the answer is the third one, t<span>he presence of oxygen–bound hemoglobin makes it bright red.
I hope my answer helped you</span>
Answer and Explanation:
The Cretaceous–Paleogene extinction, which occurred around 66 million years ago, is defined as a mass extinction that wiped out around three-quarters of species on Earth.
Among the organisms that disappeared during this event, we find mammals, birds, fish, sharks, pterosaurs, birds, reptiles, insects, and some plant species.
This event is marked by the presence of a sediment layer known as the K-Ph boundary which showed important levels of iridium, an element that is abundant in craters. Therefore, after its discovery, scientists hypothesize this extinction occurred due to the impact of the giant Chicxulub crater which changed the conditions of the atmosphere.
Im pretty sure that it is the letter ::::A ..
hope this helped xoxo
