What is the best reason a scientist might use a model to represent the solar system?

A-mn has a cubic structure with a0 0.8931 nm and a density of 7.47 g/cm3. b-mn has a different cubic structure, with a0 0.6326 nm and a density of 7.26 g/cm3. the atomic weight of manganese is 54.938 g/mol and the atomic radius is 0.112 nm. determine the percent volume change that would occur if a-mn transforms to b-mn.

The sum of the normal stresses does not change as the stress state rotates through an angle. a)-trune b)- false

Brief discuss how the presence of dislocations in crystal structures can be an advantage and a disadvantage to engineer and designers.