natron - This is salt that was used to dry the body during mummification.
A naturally occurring salt used as a preservative and drying agent during mummification. It is a mixture of four salts that occur in varying proportions: sodium carbonate, sodium bicarbonate, sodium chloride and sodium sulfate.
necropolis - This is a special type of city where there were lots of burials.
Normally describes large and important burial areas that were in use for long periods. From Greek nekros (corpse) and polis (city).
neter - This is a word the Egyptians used for the forces of nature.
This seems to be the Egyptian word for the forces that are god or a group of gods, although the exact meaning is unknown.