8. The transition or d block elements, in which electrons enter
inner d orbitals, form a well-defined series with many common and
characteristic features. They are all metals; those on the right of the
block are softer and have lower melting points than those on the left
(Table 13,2, p. 360). Many are sufficiently resistant to oxidation, corrosion
and wear to make them useful in everyday life. They have
similar ionisation energies (Figure L6 often give ions of variable
valency, and readily form complexes (pp. 46, 362) many of which are
coloured. However, regular gradations of behaviour, either across a
series or down a group are much less apparent than in the typical s and
p block elements. The elements at the end of each transition series—
copper and zinc in Period 4, silver and cadmium in Period 5 and gold
and mercury in Period 6—have d orbitals which are filled. When
copper and silver form the copper(I) ion Cu+ and the silver ion Ag +
respectively, and zinc and cadmium the ions Zn2+ and Cd2+ respectively,
the inner d orbitals remain filled. Are these elements and ions
properly called "transition' elements and ions? We shall see in Chapters
13 and 14 that their properties are in some respects intermediate
between those characteristic of a transition metal and a non-transition
metal. Thus zinc, for example, is like calcium in some of its compounds
but like a transition metal in others. Again, silver has some properties
like an alkali metal but also has "transition-like' properties.
8. The transition or d block elements, in which electrons enterinner d orbitals, form a well-defined series with many common andcharacteristic features. They are all metals; those on the right of theblock are softer and have lower melting points than those on the left(Table 13,2, p. 360). Many are sufficiently resistant to oxidation, corrosionand wear to make them useful in everyday life. They havesimilar ionisation energies (Figure L6 often give ions of variablevalency, and readily form complexes (pp. 46, 362) many of which arecoloured. However, regular gradations of behaviour, either across aseries or down a group are much less apparent than in the typical s andp block elements. The elements at the end of each transition series—copper and zinc in Period 4, silver and cadmium in Period 5 and goldand mercury in Period 6—have d orbitals which are filled. Whencopper and silver form the copper(I) ion Cu+ and the silver ion Ag +respectively, and zinc and cadmium the ions Zn2+ and Cd2+ respectively,the inner d orbitals remain filled. Are these elements and ionsproperly called "transition' elements and ions? We shall see in Chapters13 and 14 that their properties are in some respects intermediatebetween those characteristic of a transition metal and a non-transitionmetal. Thus zinc, for example, is like calcium in some of its compoundsbut like a transition metal in others. Again, silver has some propertiesเช่นโลหะแอลคาไลเป็น แต่ยัง มี "เปลี่ยนเหมือน ' คุณสมบัติ
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