How are atoms and elements related?

What is the composition, in atom percent, of an alloy that consists of 4.5 wt% pb and 95.5 wt% sn? the atomic weights for pb and sn are 207.19 g/mol and 118.71 g/mol, respectively.(a) 2.6 at% pb and 97.4 at% sn(b) 7.6 at% pb and 92.4 at% sn(c)97.4 at% pb and 2.6 at% sn(d) 92.4 at% pb and 7.6 at% sn

What is the molarity of the solution produced when 145 g of nacl is dissolved in sufficient water to prepare 2.75 l of solution?

[08.05] which answer provides the correct name for name the following hydrocarbon? (2 points) moving left to right: a hydrocarbon chain made of a methyl group (ch subscript three) single bond carbon triple bond carbon single bond ch bonded to a methyl group (ch subscript three) and a chain including a methelyne group (ch subscript two) single bond methyl group (ch subscript three). 4-ethyl-2-pentyne 4-methyl-2-hexyne 2-heptyne 4-methy-hexane