(2) U-238 is the radioisotope used in dating geological formations. Uranium-238 has a half-life of 4.46 billion years, which makes it suitable to date such old formations.
The other options do not have such long durabilities and half-lives.
<span>Strontium
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Answer:
A. LST
Explanation:
• 1st Law: The path of each planet around the Sun is an ellipse with the Sun at one focus.
• 2nd Law: The line from the Sun to any planet sweeps out equal areas of space in equal time intervals.
• 3rd Law: The square of the orbital period of a planet is directly proportional to the cube of the average distance
Answer:
Subscripts are small numbers right next to the letters
Explanation:
Xenon is a noble gas element that is highly unreactive. It has completely filled outermost shell and very stable on its own.
Xenon is an element with an atomic number of 54; it has an electronic configuration below:
[Kr] 4d¹⁰ 5s² 5p⁶
As we can see, the outermost energy shell, level 5; has a configuration of:
5s² 5p⁶
S is a sublevel with 2 electrons made up of 1 orbital
P is a sublevel with 6 electrons made up of 3 orbitals
These orbitals are filled in xenon and so it is stable and will not want to react with any other kind of atom.
This is why it is unreactive.
Learn more:
Noble gas brainly.com/question/10874792
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