ASAP PLEASEE 1. Bobby and Jane dissolve 26.8 g of solid potassium iodide (Kl) in water, then pour the solution into an excess of concentrated lead (ll) nitrate. Jane carefully filters the
resulting yellow precipitate from the solution and dries the solid overnight. The
following day, Bobby finds the mass of the precipitate (which he knows to be Pbly) to
be 34.8 g. What is the percent yield of PbI2 in Bobby and Jane's reaction?
KI=165.99g/mol
PbI2= 461.01g/mol
2KI + Pb(NO3)2 – 2KNO3 + Pbl2
Round your Answer to One Decimal Place.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.  

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.