On This Day: 08 May 1974 Canadian Government of ---------- falls ?

Questions

which nobel laureate renounced his knighthood in 1919 following the amritsar massacre of 400 indian demonstrators by british troops?

who discovered radioactivity in uranium?

what was the old term for hydrogen?

who, while working in cambridge, was the first to calculate, accurately, the density of the earth?

name the four groups of elementary particles, no commas, in alphabetical order?