If element X consists of 64.6% of atoms with a mass of 34.0 u, 18.2% of atoms with a mass of 35.0 u, and 17.2% of atoms with a mass of 36.0 u, what is the average atomic mass of element X to the nearest hundredth?

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

How do you lengthen a pattern piece? (family and consumer science, sewing)

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?