The answer is A, do you want me to explain it? It’s pretty simple, you just need to follow all the signs in brackets and match them in those in the answer
If the grade of the ore is 37.3% nickel, then the unknown quantity to get 10 grams of nickel is 0.373 x = 10 grams or x = 10/0.373=26.8 grams or 0.0268 kg needed to dig up to recover the 10 grams of nickel. At this grade of ore, 1 kilogram would yield 373 grams of nickel.
18)
a. Ra
d. Ag
19)
a. C
b. Br
c. Mg
20)
a. S
b. Br
c. O
Sorry wasn’t sure about some of them in #18
Hope the notes are helpful.
Inter-molecular forces. The greater the attraction between particles the more energy required to break the forces or "melt" them.
Please mark as brainliest if satisfied with answer.