How many molecules are in 38.4 moles of NF3?

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

Which term best describes the form sound takes as it travels away from a drum (a- gas)(b-music) ( c-waves) (d-particles

200. ml of 3.00 m nacl solution is diluted to a final volume of 500. ml. what is the molarity of the final solution?