Skip to main content

RELATIVE ATOMIC MASS,MOLECULAR MASS and FORMULA MASS

RELATIVE ATOMIC MASS
Relative atomic mass is the mass of an atom of an element as compared to the mass of an atom of carbon taken as 12.
Relative atomic masses are measured in atomic mass units (amu).
1 a.m.u. is 1/12th part of mass of an atom of C-12.
1 a.m.u.= 1.661×10-27kg
               = 1.661×10-24g
For example: Hydrogen and oxygen have relative atomic masses 1.008 amu and 15.9994 amu respectively.
MOLECULAR MASS 
The sum of the relative atomic masses of all the elements present in the molecule of a compound is called molecular mass.  Example: H2O = 18 a.m.u., CO2 = 44 a.m.u.
FORMULA MAS 
The sum of the relative atomic masses of all the elements present in the formula unit of the compound is called formula mass Example: NaCl =58.5 a.m.u.,CaCO3 = 100 a.m.u.

Comments

Post a Comment

Popular posts from this blog

Mr chips important short questions.

Chapter#1 Question # 1:How does a person spend his time in old age after retirement? Answer : After retirement when a person becomes old, he has nothing to do. His time seems to pass like lazy cattle moving across a landscape(valley). Question # 2:Why did Chips keep on adjusting his timetable according to the school bells even after the retirement? Answer : After spending more than forty three(43) years at Brookfield, it was not possible for Chips to break his ties with school. He began to live across the road and Mrs. Wickets. That's why it was possible for Chips to keep on adjusting his timetable according to the school bells. Question # 3:How did Chips voice sound in old age? Answer : Although Chips had become old yet he did not loose the zeal and zeast for the life. So his voice remained resonant and lively even in his old age. Question # 4:What did Chips do before going to the bed? Answer : Chips was spending a pleasant and placid time at Mrs. Wickets after his retirem...
Post a Comment
Read more

DISPLACMENT, DISTANCE, SPEED, VELOCITY AND ACCELERATION

Displacement: Shortest distance between two points is called displacement                                                                OR The displacement is a change in the position of body form its initial position to final position Unit:  SI unit of displacement is metre (m)                    Dimension:             The dimension of displacement is [L] VELOCITY: The time rate of change of displacement is known as velocity. It is a vector quantity. Its direction is along the direction of displacement. Mathematically...
Post a Comment
Read more

DEFINING CHARACTERISTICS (DEFINITION)

Sometimes the definition of some word is written and the students are asked to find the word whose definition has been given. Example: 1.  The chemist tried to produce _____ that could cure all the diseases.       A) symptom                                                    C) medicine                      B) injection                                                       D) panacea More Examples: 2.  John was a ________________ , who does not  believe that any t...
Post a Comment
Read more