Question

1). To achieve an octet in the valence energy level, an oxygen atom will gain two electrons.

True
False
2). The abbreviated electron configuration for cesium is [Kr] 5s24d105p66s1.
True
False

Answer 1

Answer:1) True

2)false

Step-by-step explanation:

1) oxygen has six electrons in its outermost shell, 1s2 2s2 2p4. This implies that it needs only two more electrons to attain the noble has configuration hence it gains two electrons to form a divalent negative ion.

2) The correct shortened electronic configuration for Ceasium is shown below, followed by the longhand electronic configuration of the element.

Caesium:

Electron configuration:

[Xe]6s1

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1

Answer 2

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 of mainly main-group elements tends to get combined in such a way that each atom gets eight electrons in its last valence shell, giving it the nearest same electron configuration as a noble gas".

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
`1 s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(10)4s^(2) 4p^(6)`

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
`1 s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(10)4s^(2) 4p^(6) 4d^(10) 5s^(2) 5p^(6) 6s^(1)`

which can be also written as Cs = [Kr]
`4d^(10) 5s^(2) 5p^(6) 6s^(1)`