if 1.0 mole of neon, 2.0 moles of helium, and 3.0 moles of argon are mixed, what is the mole fraction of helium?

Can someone me with 3 and 4 plz. this is for masteries test.

An atom with 7 protons, 6 neutrons, and 7 electrons has an atomic mass of amu. (enter a whole number.) numerical answers expected! answer for blank 1:

Read "who built the pyramids? ”. leave this link open while you answer the questions throughout the assignment. give at least two reasons why some people claim the pyramids of giza were constructed by aliens.