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.
Any substance that triggers an immune response is an antigen(s).
Answer:
The answer is D.
Explanation:
The friction of the brake rubbing the rim of the front tire causes the bike to slow down and stop.
Answer:
D. guard cells.. this is answer i think..
The answer is A. number of pots
