The tilt of Earth on it's axis
It is an example of a physical change because the chocolate changes from a solid to a liquid however it’s chemical composition is not changed so it’s a physical change.
The average atomic mass of the atom that has the following isotopes in the following abundances: 20 10Z 30% , 19 10Z10% , 18 10Z 60% is 18.7.
<h3>How to calculate average atomic mass?</h3>
The average atomic mass of an isotopic element is the weighted average of the atomic masses of the naturally occurring isotopes of an element.
According to this question, the atom has the following isotopes in the following abundances: 20 10Z [30%] = 30/100 × 20 = 6
19 10Z [10%] = 10/100 × 19 = 1.9
18 10Z [60%] = 60/100 × 18 = 10.8
The sum of these masses is the average atomic mass and is calculated as follows:
6 + 1.9 + 10.8 = 18.7
Therefore, the average atomic mass of the atom that has the following isotopes in the following abundances: 20 10Z 30% , 19 10Z10% , 18 10Z 60% is 18.7.
Learn more about average atomic mass at: brainly.com/question/13753702
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Different radioactive nuclides decay into their respective daughter nuclides at distinct rates. Some of the nuclides decay briskly, while others decay gradually. The time it consumes for half of the parent nuclide in a radioactive sample to decay to the daughter nuclides is known as the half-life of the radioactive sample.
The nuclides, which decay briskly exhibit short half-lives and are very active. The half-life can be utilized to find the rates of radioactive decay. In the given question, the half-lives of various nuclides are given. So, the order to the most active (shortest half-life or largest number of decays per second) to least reactive (largest half-life or the smallest number of decays per second) is:
Tc-99m > Y-90 > In-111 > I-131
Answer:
Red was originally selected for the same reason. Over a century ago, red was a nice bright color that set fire apparatus apart from most vehicles on the road. Red became traditional, and most fire departments stayed with it. Some firefighters like yellow trucks, some prefer traditional red.
