Answer is: reactivity series or activity series.
Reactivity series is an empirical progression of a series of metals, arranged by their reactivity from highest to lowest (alkaline metals have highest reactivity and Noble metals lowest reactivity). This series are used to summarize information about the reactions of metals with acids or water, double displacement reactions (more reactive metals displace metals with lower reactivity) and the extraction of metals from their ores.
Every element is made up of the same type of atom eg.hyrdogen is made of hyroden atoms
Answer:1,25 km per minute
Explanation: