ASAP!!! Explain: Why do black lines appear on the absorption spectrum of the sun?

14. complete and balance the equations for the single displacement reactions. a. zn + pb(no3)2 -> b. al + niso4 -> 15. complete and balance the equations for the double displacement reactions. a. agno3(aq) + nacl(aq) -> b. mg(no3)2(aq) + koh(aq) -> 16. complete and balance the equations for the combustion reactions. a. __ ch4 + o2 -> b. __ c3h6 + o2 -> c. + o2 ->

The boiling point of propanoic acid is higher than that of 1-butanol because: propanoic acid has a higher molecular weight than 1-butanol. propanoic acid is more soluble in water than 1-butanol. propanoic acid is a better hydrogen bond donor than 1-butanol. propanoic acid forms hydrogen bonded dimers and 1-butanol does not. 1-butanol forms hydrogen bonded dimers and propanoic acid does not.

Which part of earth’s surface receives the most direct rays from the sun? a) equator b) ocean c) poles d) mountains