pacific

thank u very much .... u r really experiance in chemistry

i have done 1st,2nd,3rd & 4th....but not sure from 2nd & 3rd... please if u can solve them note me ... my email is : almosila@hotmail.com

You would like to be able to physically separate different materials in a scrap recycling plant. Describe some possible method that might be used to separate materials such as polymers, aluminum alloys, and steel from one another. An optical fiber for telecommunication is made of SiO2 glass (density= 2.20 Mg/m3). How many Si atoms and how many O atoms are present per millimeter of length of a fiber 10 micrometer in diameter? Make an accurate plot of FA versus r for an Mg2+ - O2- pair. Conceder the range of r from 0.2 to 0.7 nm. Describe the quantum number for each of the 11 electrons in sodium. If the attractive force between a pair of Mg2+ and S2- ions is 1.49x10-8 N and if the S2- ion has radius of 0.184, calculate a value for the ionic radius of the Mg2+ ion in nanometer. The lattice constant for BCC tantalum at 20 oC is 0.3302 nm and its density is 16.6 g/cm3. Calculate a value for its atomic mass. Cobalt has an HCP crystal structure, an atomic radius of 0.1253 nm, and a c/a ratio of 1.623. Compute the volume of the unit cell for Co. Niobium has an atomic radius of 0.1430 nm and a density of 8.57 g/cm3. Determine whether it has an FCC or BCC crystal structure. BCC = Body-Centered Cubic FCC = Face-Centered Cubic HCP = Hexagonal Close-Packed :eek:

hello... i'm new .... i hope find here the best informations ...I like science and chemestry

thanks