Guys help with this question please!

This is how zirconium appears in the periodic table. rounded to the nearest whole number, how many electrons are in an atom of zirconium?

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

If forces acting on an object are unbalanced. true or false