The number of hours required : 37.2 hours
<h3>Further explanation</h3>
Given
⁴²K (potassium -42)
Required
The number of hours
Solution
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually, radioactive elements have an unstable atomic nucleus.
Based on Table N(attached), the half-life for ⁴²K is 12.4 hours, which means half of a sample of ⁴²K will decay in 12.4 hours
For three half-life periods :

Radiography techs are trained to operate medical equipment that uses X-rays and other types of radiation. Ultrasound techs, referred to professionally as diagnostic medical sonographers, operate equipment that uses high-frequency sound waves to create images.
(Credits to google)
Hydrocarbons. They usually burn. In fact, I can't think of one that does not.
- Dalton reported that seven pounds of Oxygen reacted with one pound of hydrogen to form water, but accurate modern experiment gives eight pounds to one.
- Lavoisier reported that water contains Oxygen 5.6 times more than hydrogen by weight.
- Dalton assumed that water contains 1 atom of oxygen and 1 atom of hydrogen and concluded that the relative weight of O must be 5.6 times as large as the H atom.
- By determining the relative mass we will be able to determine for example that one element has twice the mass of a second element.
Transferring heat through electromagnetic waves