Câu 1: Cân bằng các phương trình phản ứng oxi hóa – khử bằng phương pháp thăng bằng electron. Cho biết chất oxi hóa và chất khử của mỗi phản ứng. a) Fe2O3 + H2 -> Fe + H2O b) Cu + HNO3 -> Cu(NO3)2 + NO + H2O

answer: a tank of height h is filled with water and sits on the ground. water squirts from a hole at a height y above the ground and has a range r. for two y values, 0 and h, r is zero. determine the value of y for which the range will be a maximum.

explanation:

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.

it's c (engineer's do their work with mechanical stuff not on any living being)

5.6⋅10−^19  j

do you need the explaination?