A generic element, A, is composed of two isotopes, 208A and 204A. 208A has a natural abundance of 55% and an isotopic mass of 207.98 amu, and 204A has a nautral abundance of 45% and an isotopic mass of 203.97 amu. What is the average atomic mass of this element? Please choose the correct answer from the following choices, and then select the submit answer button. Answer choices

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.