Based on sound evidence, most face masks protect only 1,000 nm+ in particle size. The coronavirus is only 80-100 nm in size. Because of this, the most face masks can protect you against is pollen. It's like comparing a grape to a grapefruit. It's a false sense of security. Now my question: Is it worth it?

i wish i could but this one is weird give me abc and i can solve it.

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.