It measures the acidity/basic level, that rules A out
hope this helped a little
Answer:
Explanation:
Which is more reactive hydrogen or oxygen?
Hydrogen is not particularly reactive. For example, just mixing hydrogen and oxygen gas will not cause a reaction at room temperature, but many metal elements oxidize at least on the surface in air. ... It is combustible because oxygen wants electrons and takes them from hydrogen to form water.
Answer:
The weak acid is - E. 
Explanation:
Ammonia is a strong base, which in turn make it to be a weak acid.
As, the rest of the options are acid and therefore furnish hydrogen ions when dissolved in water, making them strong acid.
And ammonia dissolves in water to form its conjugate ammonium ion and hydroxide ion, therefore making the solution basic.
Hence, from the given options, the correct option is E. 