Sodium and aluminum are in the same period, and therefore have similar chemical properties. It's B.
When you're simplifying equations, you have to collect the like terms (the similar ones, eg- fractions would be like terms, and so would letters).
When you're simplifying, you also have to take note of the operation before the equation.
1) Firstly, collect the like terms of M (M and -4M). As M comes before -4M, you have to add -4M to M. As -4M is a negative, this overwrites the addition, and this becomes M-4M. This then gives you -3M. The same applies to the fractions, as you have -1/6 + 5/6, you have to add 5/6 to -1/6, and this gives you 4/6, or 2/3 simplified. Therefore, you put these together- and this gives you -3M + 4/6, however, you normally have a negative number second, so one this has been rearranged, this gives you 4/6-3m.
2). Same applies to this one, you also have to collect the like terms of W. 2.3W and -3W. You simply have to subtract -3W from 2.3W, and this gives you -0.7W. You now have to collect the numbers, and you have -7 and 8. 8 is a positive, therefore, you have to add 8 to -7, giving you 1. Therefore, when you collect the like terms, this gives you -0.7W+1. As aforementioned, you cannot have a negative first, so one this is rearranged, this gives you 1-0.7W
Hope this helps :)
The main ideas shaping US imperialism were "Manifest destiny" and the "White man's burden". Manifest destiny refers to the 19th century belief that the United States were meant to expand across North America because of the particular excellence of its (white) people and (democratic) institutions. This lead to the Trail of Tears, among other atrocities. Once the US reached the Pacific Ocean, new lands came into view (Puerto Rico, the Phillipines). Manifest destiny became entwined with the idea that "civilized" nations had a moral obligation to colonize other peoples, which Rudyard Kipling summed up in his poem "White Man's Burden". The tensions in this "benevolent imperialism" were never fully resolved; the US invasion of Irak was launched under similar pretenses (the invasion was "for the good" of those invaded). The idea that other peoples have a right to self determination regardless of their level of development has not yet become accepted by the great powers, including the US.
