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.
The machine found no kidney stones and the patient is healthy
Answer:
28 day orbit around Earth.
Explanation:
This is called the Lunar phase. The lunar phase or phase of the Moon is the shape of the directly sunlit portion of the Moon as viewed from Earth.
The awnser would be D the tilt on the earth on its axis
Answer:
<em>This question includes the following options:</em>
<em>A.</em><em>1 - </em><em>B.</em><em>3 - </em><em>C.</em><em>6 - </em><em>D</em><em>.8 -</em><em> E.</em><em> 12</em>
PCR which stands for <em>"Polymerase Chain Reaction"</em> is a molecular biology procedure to quickly multiply a small sample of DNA into millions or billions of DNA copies for studying purposes.
<em>"Unlinked"</em> signifies that the markers are present in 6 various chromosomes, but to amplify those markers we would need <em>(</em><em>12</em><em>)</em> unique primer sequences, due to it is required to have the reverse and forward primers for every marker; thereby the answer is <em>(</em><em>E.</em><em>)</em>
