Which of the following is not a characteristic of interstitial compounds of transition elements?
The formulae of these compounds do not correspond to any normal oxidation state
They have melting points higher than those of pure elements
They are very hard and some compounds approach diamond in hardness
They do not exhibit metallic character

In which of the following coordmation compounds do the transition metals have an oxidation number of +6?

Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic properties of interstitial compounds? I. They have high melting points in comparison to pure metals. II. They are very hard. III. They retain metallic conductivity. IV. They are chemically very reactive.

Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following are the characteristic properties of interstitial compounds? I. They have high melting points in comparison to pure metals. II. They are very hard. III. They retain metallic conductivity. IV. They are chemically very reactive.

Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following are not characteristic properties of interstitial compounds? I. They have high melting points in comparison to pure metals. II. They are very hard. III.They retain there metallic conductivity IV. They are chemically reactive

Assign reasons for the following : (i) The enthalpies of atomisation of transition elements are high. (ii) The transition metals and many of their compounds act as good catalyst. (iii) From element to element the actinoid contraction is greater than the lanthanoid contraction. (iv) The E^(@) value for the Mn^(3+)//Mn^(2+) couple is much more positive than that for Cr^(3+)//Cr^(2+) . (v) Scandium (Z = 21) does not exhibit variable oxidation states and yet it is regarded as transition element.

Which of the following are correct about Zn,Cd,Hg I) They exhibit enthalpy of atomisation as the d-subshell is full II) Zn,Cd do not show variable oxidation states, Hg can show +1,+2 states III) Compounds of Zn,Cd,Hg are paramagnetic IV) They are soft metals

Which of the following are correct about Zn,Cd,Hg I) They exhibit enthalpy of atomisation as the d-subshell is full II) Zn,Cd do not show variable oxidation states, Hg can show +1,+2 states III) Compounds of Zn,Cd,Hg are paramagnetic IV) They are soft metals

The elements of group II are known as alkaline earth metals. The electronic configuration of these elements . The electronic configuration of these elements is ns^(2) and oxidation state is +2 . They have higher ionization energy than alkali metals in their respective period due to their small size and completely filled s-orbital. These elements give characteristic colour to bunsen flame. magnesium is used in the preparation of Grignard agent (RMgX) which is used in organic chemistry for preparation of sevaral organic compounds like alcohols. acids, hydrocarbons. Q. Brick red colour of flame test is gives by

Explain the following observations : (i) Many of the transition elements are known to form interstitial compounds . (ii) There is a general increase in density from titanium (Z =22) to copper (Z = 29). (iii) The members of the actinoid series exhibit a larger number of oxidation states than the corresponding members of the lanthanoid series.

The IUPAC definition of a transition element is that it is an element that has an incomplete d-subshell in either the neutral atom or its ion. Thus the group 12 elements are member of the d-block but are not transition elements. Chemically solft members of the d-block occurs as sulphide minerals and are partially oxidised to obtain the metal, the more electropositive 'hard' metals occurs as oxides and are extracted by reduction. Opposite to p-block elements, the higher oxidation states are favoured by the heavier elements of d-block Metals on the right of the d-block tend to exist in low oxidation states and form complexes with the ligands. Square-planar complexes are common for the platinum metals and gold in oxidation states that yield d^8 electronic configuration, which include RH(I),Ir(I),Pd(II),Pt(II) and Au(III). The most distinctive features/properties of transition metal complex is their wide range of colours.The crystal field theory attributes the colour of the coordination compounds to d-d transition of the electron.It is important to note that (a) in absence of ligand, crystal field spilling does not occur and hence the substances is colourless, (b) the type of ligand also influences the colour of the complexes. Which of the following has dsp^2 hybridisation and is diamagnetic in nature ? (i) Na_4[Cr(CO)_4] , (ii) [Ni(DMGH)_2] , (iii) [PtHBr(PEt_3)_2] (iv) [As(SCN)_4]^(3-) , (v) [AuBr_4]^(-)