Answer
The electron configuration of titanium is $$1s^22s^22p^63s^23p^64s^23d^2$$
A titanium atom has 2 valence electrons.
Work Step by Step
1) Find out the number of electrons in a titanium atom
The atomic number of titanium is 22. That means there are 22 electrons in a titanium atom.
2) Arrange the electrons into the shells and subshells in order of increasing levels of energy
- The first 2 electrons occupy the lowest level subshell $1s$.
- The next 2 electrons occupy the next lowest level subshell $2s$.
- The next 6 electrons occupy the next lowest level subshell $2p$.
- Moving on, the next 2 electrons occupy subshell $3s$.
- The next 6 electrons occupy subshell $3p$.
- The next 2 electrons occupy the next lowest level subshell $4s$.
- The last 2 electrons occupy the next lowest level subshell $3d$.
Therefore, the electron configuration of titanium is $$1s^22s^22p^63s^23p^64s^23d^2$$
We are told that the valence electrons, in most cases, are those in the outermost occupied shell. Here $n=4$, the outermost shell, has 2 electrons in subshell $4s$.
Therefore, a titanium atom has 2 valence electrons.
