The lanthanide elements react with oxygen to give compounds of the type Ln203 (where Ln stands for a lanthanide element). However, there are interesting erceptions, such as a common oxide of terbium TbxOy. Given that the compound is 73,945%Tb, what is its formula

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.

the dissolution of polymer can be thermodynamically described in 2 steps.