Which of these metals silver iron magnesium potassium or zinc will give the most violent reaction with water and why?
Potassium is the most reactive. All of the elements in the first
column of the periodic table are extremely reactive to water. These
elements all have on more electron than the stable noble gas
configuration (an octet in the valence shell), and so by getting
rid of that extra valence electron, the element becomes much more
stable. In contact with water, these elements will give this extra
electron off to the water, forming hydroxide (OH-) and becoming a
positive ion. For example, when you add potassium metal (K) to
water, you will form the positive ion K+, which has the same
electron configuration as argon, with a completely filled valence
shell. The other metals listed will not react very quickly at all
with water (unless it is very acidic water).