Which of the following shows three elements in order of decreasing conductivity?

a. zn, pd, ag
b. pd, ag, zn
c. ag, pd, zn
d. zn, ag, pd

which of the following is the name of a metal?
a. k
b. potassium chloride
c. potassium
d. kci

C. Ag, Pd, Zn

C. Pottasium

Explanation:

It is a known fact that silver (Ag) is one most conducting metals so clearly Ag is most conducting than Zn (Zinc) and Pd (Palladium). so answer is C

in the second question

A. K is the symbol off Metal potassium in the periodic table

B. Potassium chloride is a Metallic salt not a metal

C. Potassium is a name of metal

D. KCl is The symbol of potassium chloride

so C is the answer

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation:

a corroding iron, if that's one of your choices