'Gram', 'kilogram', and 'metric ton' are units of mass, not weight.
'Pound' can be either a unit of mass or of force. Most people
use it most of the time to mean weight.
Sinkholes and caves are 2 reasons. hope that helped
For instance, in an alkaline battery, the anode is typically made of zinc, and manganese dioxide acts as the cathode. And the electrolyte between and inside those electrodes contains ions. ... These free electrons congregate inside the anode (the bottom, flat part of an alkaline battery)
Hope this helps:)