Because 4s is a lower energy level and 3d is higher. In fact, s levels should, strictly, be written first before d levels when writing electron configurations.
The element that contains five electrons in its 3d orbital is manganese (Mn). Manganese has an atomic number of 25, and its electron configuration is [Ar] 4s² 3d⁵. This means it has five electrons in the 3d subshell.
Vanadium (V) contains 5 electrons in its 3d orbitals.
The electron configuration 4s²3d⁸ corresponds to the element nickel (Ni), which has an atomic number of 28. This configuration indicates that nickel has a total of 28 electrons, with the outermost electrons in the 4s and 3d subshells.
Sc is a 3d element. It has 21 protons and 21 electrons.
The electron configuration Ar4s²3d⁷ corresponds to the element cobalt (Co), which has an atomic number of 27. In this configuration, "Ar" represents the noble gas argon, which accounts for the first 18 electrons. The 4s² indicates two electrons in the 4s subshell and the 3d⁷ indicates seven electrons in the 3d subshell, totaling 27 electrons for cobalt.
The element that contains five electrons in its 3d orbital is manganese (Mn). Manganese has an atomic number of 25, and its electron configuration is [Ar] 4s² 3d⁵. This means it has five electrons in the 3d subshell.
The element in the fourth period with 3 3d electrons is titanium (element #22).
Vanadium (V) contains 5 electrons in its 3d orbitals.
There are 3d^10 electrons in arsenic, as it is located in the 4th period of the periodic table.
1s2 2s2 2p6 3s2 3p6 4s2 3d5
4s electrons are lost first. The reason is because this is more energetically favored than losing d-electrons. As a result, all transition metals can bear a +2 charge. In many cases, d-orbital electrons can also be lost. Consider V+2 and V+3; the first has all of the d-orbital electrons (the 3 belonging to Vanadium) and has lost the 2 4s electrons. V+3 has lost the 2 4s electrons and 1 3d electron.
The extra electron would go into a 4s orbital because 4s can hold up to 2 electrons before 3d can be filled.
B. 1s22s22p63s23p64s23d5----Chromium: [Ar]1s22s22p63s23p63d54s1Manganese: [Ar]1s22s22p63s23p63d54s2
The electron configuration 4s²3d⁸ corresponds to the element nickel (Ni), which has an atomic number of 28. This configuration indicates that nickel has a total of 28 electrons, with the outermost electrons in the 4s and 3d subshells.
Sc is a 3d element. It has 21 protons and 21 electrons.
The element with one 3d electron is manganese (Mn), which has the electron configuration [Ar] 3d^5 4s^2.
The electron configuration Ar4s²3d⁷ corresponds to the element cobalt (Co), which has an atomic number of 27. In this configuration, "Ar" represents the noble gas argon, which accounts for the first 18 electrons. The 4s² indicates two electrons in the 4s subshell and the 3d⁷ indicates seven electrons in the 3d subshell, totaling 27 electrons for cobalt.