Answer 1)
True
Explanation : To achieve an octet state in valence energy level, an oxygen atom will gain two electrons because as per the definition of octet rule, "The atoms<span> of mainly main-group elements tends to get combined in such a way that each </span>atom gets eight electrons in its last valence<span> shell, giving it the nearest same </span>electron<span> configuration as a noble gas". </span>
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</span>So, in the case of oxygen which has 8 electrons and it will accommodate 2 electrons in its first shell and rest 6 in its last valence shell. In order to achieve the octet state it's easier for the atom to gain 2 electrons rather than giving up rest 6 electrons. Hence, it is true that it gains 2 electrons to complete the octet state.
Answer 2)
True
Explanation : The electronic configuration of Krypton [Kr] is
The abbreviated form of any element can be written as the nearest noble elemental configuration, along with the remaining extra distributed electrons in other orbitals;
Hence, the electron configuration of Cesium [Cs} is
which can be also written as Cs = [Kr]
The word that indicates a contrast is However.
In English, the word "however" is used to introduce a statement that contrasts with something that was said previously.
Lewis structures have the distinct characteristic of electron dots drawn around an atom. They represent the valence electrons or the electron located at the outermost shell of the atom that takes part in chemical reactions.
For neutral compounds, they simply add the valence electrons of the individual atoms. This is because it has no charge. Whatever the net charge of the compound is, that would be added, as well.
For example, the HCl atom's valence electrons would be 1 + 7 + 0 = 8. Therefore, you draw 8 electron dots around the HCl compound.
The charges on a droplet can be used to represent the number of electrons carried by this droplet.
In other words:
a droplet having a charge of 1.60 x 10^-19 has 1.60 x 10^-19 electrons while a droplet having a charge of 3.15 x 10^-19 has <span>3.15 x 10^-19 electrons.
From the observations:
The fact that the droplets carried different charges signifies the fact the different droplets carried different numbers of electrons</span>
The answer for the first question is A. Proton is the subatomic particles which adds most of the mass of an atom as well as the neutron since they have the same mass. Photon, on the other hand, is not one of the subatomic particles.