Answer:
C. Potassium-19
.
Explanation:
Hello!
In this case, since isotopes are known be atoms of the same element with equal atomic number but different mass number, we can consider the case of carbon which has two natural occurring ones, carbon-12 and carbon-13 whereas carbon-12 has the greatest abundance. However, isotope notation may take two forms:
1. Symbol of the element followed by a dash indicating the mass number of the isotope, for instance: C-12, K-39, and so on.
2. Name of the element followed by a dash indicating the mass number of the isotope, for instance: Carbon-12, Potassium-39, and so on.
In such a way, the improper isotope notation is C. Potassium-19
, considering that A should be K-39 because atomic symbol of potassium is K, not k.
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Answer:
It is the smallest planet found in the habitable zone.
Explanation:
The correct formula of the oxide that forms when X burns in oxygen is X2O3.
Ionization energy is defined as the energy required to remove an electron from an atom. There are as many ionization energies present in an atom as there are electrons in that atom.
However, we can know the ionization energy values that belong to electrons in the outermost shell because they lie close together. If we go further into the inner shells, there is a sudden quantum jump in ionization energy values.
The element X must have three valence electrons because 631 ,1235, 2389 all refer to ionization energies of electrons in the valence shell. As we get into a core shell, there is a sudden jump hence the fourth and fifth ionization energies are 7089 and 8844 respectively.
The correct formula of the oxide that forms when X burns in oxygen is X2O3.
Learn more: brainly.com/question/16243729
