Is bubble chamber one of your choices? Bubble chamber sounds like a good fit for the question.
Answer:
oxygen is an element because it is a pure substance which cannot be split into simpler substances by chemical means
Answer is
C. 2.07 M
For explanation
M1V1 = M2V2
M2 = (M1V1)/V2
M2 = (1.5M x 345ml) / 250 ml
:. M2 = 2.07 M
I'm confused... is there more info?
Ionization energy is the energy required to remove an electron from a gaseous atom or ion. The first or initial ionization energy or Ei of an atom or molecule is the energy required to remove one mole of electrons from one mole of isolated gaseous atoms or ions