Because neptunium is radioactive, ingestion or inhalation can cause cancers.
Neptunium react with hydrogen forming hydrides with formulas between NpH2 and NpH3.
Any reaction occur.
Neptunium trifluoride is an intermediate for the preparation of neptunium metal.
Neptunium is a metal.
Neptunium has not a smell.
Nothing happens
You Die
pain
you die
you die...
Neptunium is an individual element; isotopes of neptunium are not separated.
You can get chemical burns along your throat and stomach if you swallow lye.