Cho 40 gam tác dụng (Al, Cu) vừa đủ với 600 gam dd HCl 14,6%. Tính% khối lượng Al, Cu

Which of the following are sources of revenue for media companies? a. direct sales to producers b.advertising and subscriptions c. online purchase d. capital investments

Which of these statements best explains why space exploration should be encouraged? it prepares humans to live without oxygen. it dispel myths about objects in space. it prevents comets and asteroids from striking earth. it creates technology to absorb harmful radiations in space.

Nuclear decay is the spontaneous decay of one element into a. an x-ray b. a ray of light c. another element