Electrons in an atom can be classified as core electrons and valence electrons. Valence electrons are those electrons which are present in valence shell and participates in bond formation. While, Core electrons are all remaining electrons which are not present in valence shell, hence not take part in bonding.
Atomic number of Selenium (Se) is 34 hence it has 34 electrons with following electronic configuration;
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁴
From electronic configuration it is found that the valence shell is 4, and the number of electrons present in valence shell are 6. So,
Core Electrons = Total Electrons - Valence Electrons
Core Electrons = 34 - 6
Core Electrons = 28
Result:
There are 28 core electrons in Selenium.
Answer:
the answer is vacum of space
Yes it’s correct.
An ionic bond is the transfer of electrons from a metal to a non-metal.
Is divided by the same number that goes into the number being divided evenly so there are no remainers
example....
2 2 1
__ ÷ __ = __
4 2 2
False, divergent boundaries are when two plates move away from each other.
