What is the different between a polar bear and a brown bears features

Polar bears have a thicker , whiter fur to help them in cooler places. 
 brown bears have less fur and brown to help them in warmer places such as texas.

Brown bear- Their coat is silvery-brown in color Brown bears have extra large claws with a big curve heavily built concave skull Brown bears are also large carnivores with body weights ranging from 300 to 700 kilograms

polar bear- adult’s weight ranges from 350 to 680 kilograms, and the body length could go up to three metres  Their legs are stocky and have a long nose and small ears , polar bears have large feet, which are advantageous to walk on the snow and to swim in the sea snow-white coat

The proton has a positive charge while the neutron has no charge they both make up the nucleus of the atom while the elections have a negative charge and surround the nucleus of the atom. the protons and electrons are used to calculate the atom's mass whereas the neutrons don't affect the mass