The element with 8 electrons in its 3d sublevel is Ni,
Nickel. The answer is letter D. The
rest of the choices do not answer the question above.
A triple bond is a type of covalent bond. It involves a sigma bond and two pi bonds (each bond involves 2 electrons). A carbon atom is capable of 4 bonds...a carbon-carbon triple bond is found in all alkynes.
Elements in the same group on the periodic table have the same number of valence electrons. The "groups" are the column (or rows). groups are vertically and periods are horizontally.