Transition Metals Have Electron Configurations with Incomplete d or f Shells

1 Transition Metals Have Electronic Configurations with Incomplete d or f Shells 

Although the transition metate are less electrow ime (more ectron ative) than the alkali and alkaline earth metal J i SiSb-d mmcmn pMUrndk j M ITall of them except copper should react with strong acids such as hydrochloric acid to produce hydrogen gas. However, most transition metals are inert toward acids or react slowly with them because of a protective layer of oxide. A case in point is chromium Despite a ralher negative standard reduction potential, it is quite inert chemically because of the formation 

Electron Configurations and Other Properties of the First-Row Transition Metals 

The electron configurations of the first-row transition metals were discussed in Section 2.2. Calcium has the electron configuration [Ar]4i. From scandium across to copper, electrons are added to the 3d orbitals. Thus, the outer electron confignration of scandinm is As 3d, that of titanium is As 3d, and so on. The two exceptions are chrominm and copper, whose outer electron configurations are and As 3d,  

When the first-row transition metals form cations, electrons are removed first from the As orbitals and then from the 3d orbitals. (This is the opposite of the order in which orbitals are filled in atoms.) For example, the outer electron configuration of Fe is 3d, not As 3d.  

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