which of the following pair of elements has similar properties ? A:Ca,Cl B:H,He. C:No,k D:k,Al
Answers
Explanation:
The transition elements or transition metals occupy the short columns in the center of the periodic table, between Group 2A and Group 3A. They are sometimes called the d-block elements, since in this region the d-orbitals are being filled in, and are also referred to as B-group elements since in most numbering systems of the columns on the periodic table the numerals of these groups are followed by the letter B. The period 4 transition metals are scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn). The period 5 transition metals are yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), and cadmium (Cd). The period 6 transition metals are lanthanum (La), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), and mercury (Hg). The period 7 transition metals are the naturally-occurring actinium (Ac), and the artificially produced elements rutherfordium (Rf), dubnium (Db), seaborgium (Sg), bohrium (Bh), hassium (Hs), meitnerium (Mt), darmstadtium (Ds), roentgenium (Rg), and the as-yet unnamed ununbiium (Uub).
The elements which follow lanthanum (Z=57) and actinium (Z=89) are called the lanthanides and actinides, respectively, and