Yes you can weigh your head.
To weigh your own head just lay down your head on a scale and the scale should show the weight of your head.
However you may need someone else to be with you so they can see the weight of your head.
A head weighs between 8 lbs to 11 lbs depending on the size of the head.
A kids head weighs between 5 to 7 lbs while an adults head weighs on average of 8 to 11 lbs.
I have weighed my head on a bathroom scale and the scale said my head weighed 8 lbs.
However I had to have my sister look at the bathroom scale to see the weight of my head because I could not see the weight myself.