Now consider the example of a positive charge q moving in the xy plane with velocity v⃗ =vcos(θ)i^+vsin(θ)j^ (i. e., with magnitude v at angle θ with respect to the x axis). if the local magnetic field is in the +z direction, what is the direction of the magnetic force acting on the particle?

The magnetic force is in the positive y direction. This can be found using the "right hand rule" of forces.

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

Sorry i dont understand the question can you rephase it?