Their Period number is common means their "Principal Quantum Numbers" are same
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Answer:
Replacement-Level Fertility
Another important population characteristic that differ btw develop nation and developing nations is relates to births is replacement-level fertility. Replacement-level fertility is the fertility rate that will result in the replacement of the parents in the population. Again, in an ideal world, the human replacement-level fertility rate would be exactly two. This would mean that each couple would produce two offspring that would replace them in the population. If this occurred, then the human population would stay at a stable rate
Answer:
IDC
Explanation:
I DON'T UNDERSTAND........
Answer: All apply
The periodic table is an arrangement of the chemical elements in the form of a table, ordered by:
-Their atomic number (number of protons)
-Their configuration of electrons
-Their chemical properties
It was progressively developed over time as the scientific knowledge advanced; for this reason many modifications and corrections might be done in the future.
Its usefulness lies in the fact that it allows the existing elements to be organized in a more structured and coherent way, according to the chemical properties they possess. Dividing the table into rows and columns, which represent the periods and groups or families.
Then, with the location and classification of an element according to its group, we can determine how it acts by knowing its chemical and physical characteristics.
This is how with this configuration can be distinguished 4 sets of chemical elements, according to the ease of their atoms to lose or gain electrons, transforming into ions: metals, semimetals, non-metals and noble gases.
This has helped to predict the existence of various elements that have not yet been discovered, because by elements already located in the table and the periodicity found, <u>there are still empty spaces that indicate the composition of the element that has not yet been found</u>.
In addition, this table helps to simplify in some way the teaching of chemical elements and facilitates their learning, as well as their usage in the development of technological innovations.
The energy of the photon emitted when an electron in a mercury atom drops from energy level f to energy level b is 3.06 eV.
<h3>Change in energy level of the electron</h3>
When photons jump from a higher energy level to a lower level, they emit or radiate energy.
The change in energy level of the electrons is calculated as follows;
ΔE = Eb - Ef
ΔE = -2.68 eV - (-5.74 eV)
ΔE = 3.06 eV
Thus, the energy of the photon emitted when an electron in a mercury atom drops from energy level f to energy level b is 3.06 eV.
Learn more about energy level here: brainly.com/question/14287666
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