Answer:
Emission of heat or light, or a color change.
<em>Answer:</em>
<em>Ello mate ! the answer is super simple it's option "A" Fe</em>
<em>Explanation:</em>
<em>Iron is a chemical element with symbol</em><em> "Fe"</em><em> and atomic number 26. It is a type of metal, that belongs to the first transition series and group 8 of the periodic table. It is by mass the most common element on Earth, forming much of Earth's outer and inner core.</em>
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 :
Answer:
D. because water and mud behaved in a similar way in the past as they do today
Explanation:
One of the fundamental theories in the field of earth science is the theory of uniformitarianism.
Uniformitarianism was proposed by James Hutton in the 18th century in Scotland. The theory states that "geologic processes occurring today have occurred in times past and that the present is the key to past".
The simple meaning of the theory is that, the processes on earth today such as weathering, erosion, e.t.c have also occurred in times past. Those processes still occur today and an understanding of such events today will help us have a better insight into the past.
Therefore, ripple marks just as they form today from action of mud and water would be formed in a similar way in the past.
