Answer:
C
Explanation:
Keystone species is the sea otter. Sea otters, playing a critical role in containing the urchin populations, prey on urchins and thus control the numbers of kelp grazers to maintain the forest.
Remember, keystone species is most often a top level predator in an ecosystem.
A radioactive element is an element which is subject to spontaneous degeneration of its nucleus followed by the emission of alpha, beta and gamma particles. All elements with atomic numbers greater than 83 are radioactive.
The given phrases that describe radioactive elements are-
They have a consistent number of particles
- the particles are alpha, beta and gamma particles.
They have a half-life that determines their rate of decay.
Explanation for other options:
Not all elements occur in nature. Radioactive decay rates may not be constant as the decay happens when a radioactive substance emits a particle. It is not possible to predict exactly when a given atom of a substance will emit a particular particle. When the radioactive element release energy and particles, it decays.
Explanation:
First do the Last, First, Then middle names of the author(s). Then the title of the article, then magazine. after that the date it was published and finally the page number the information was found on. example: Last, First Middle "title of article" title of magazine
C. Ice is less dense than water which means water condenses when it freezes allowing the ice in a lake to float on top of the water preventing the water below from freezing.
