The melting points of four impure samples of lead(II) bromide were measured. The results are shown.
Which sample is the most pure?
temperature when
the sample started
to melt/ °C
temperature when
the sample finished
melting/°C
А
342
355
B
353
360
С
365
371
D
372
373
А
o

If the element whose electric configuration ends in the d sublevel, the element is calssified as? a.inner transition b.noble gases c.representative d. transition

Using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 pb+2(aq) + 2cl -(aq). if the value of ksp was determined to be only 1.2 x 10-2: too much solid has dissolved. additional precipitate is forming. the solution is unsaturated. the ions are now combining to reduce their concentrations.

What material does not melt at any temperature