Which section of elements in the periodic table are the best conductors of heat and electricity

What does x represent in the formula for the compound xcl4?

Give the set of reactants (including an alkyl halide and a nucleophile) that could be used to synthesize the following ether: draw the molecules on the canvas by choosing buttons from the tools (for bonds and charges), atoms, and templates toolbars, including charges where needed. ch3ch2och2ch2chch3 | ch3

What is the molar mass of ca(cio4)2