Atomic Numbers are the number of protons within the nucleus,
which is 58 here.
Atomic Number=58
Mass Number is the sum of the protons and neutrons in the nucleus,
=58+82
Mass Number=140
Periodic symbol of this isotope is entirely dependent on the number of protons, 58, which corresponds to the element Cerium, abbreviated as Ce in the periodic table.
Periodic Symbol=Ce
Answer:
D)
Explanation:
Carbon.
The electronic configuration is -
Thus, 2s orbital is fully filled and p orbital can singly filled 3 electrons. Thus, Carbon has 2 singly occupied orbitals.
But in methane,
it forms 4 bonds. So, 1 electron each from 2s orbital jumps to the next orbital in the p subshell.
Thus, the configuration is:-
Thus, the valence electron configuration is:-
The answer is hydrogen (H2) because i just answered this question from Edgenuit.