Periodic table is arranged and organized with special pattern or regular variation of the properties of an element with increasing atomic number, this is called periodic trend. So periodic trend look like a repeating pattern on the periodic table.
Some of the trends are density, atomic radius,melting point, boiling point, electronegativity etc.
Answer:
The suns mass effects the solar system by having a great gravitational pull. This cause the success rate to grow lower each time.
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]
Answer:
A I did the exam and I saw A sorry if it is wrong dont have the best of memory