Which phrases describe radioactive elements? check all that apply. occur in nature decay at a constant rate have a consistent number of particles have a half-life that determines their rate of decay release energy and particles to maintain radioactivity

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.

igneous rocks which formed by the crystallization of magma at the surface of the earth called extrusive rocks. they are characterized by fine-grained textures because the rapid cooling at or near the surface did not provide enough time for large crystals to grow.