Magnesium has three naturally occurring isotopes with masses of 23.99, 24.99, and 25.98 amu and natural abundances of 78.99%, 10.00%, and 11.01%, respectively. calculate the atomic mass of magnesium. express the atomic mass in atomic mass units to two decimal places.

The answer to your question is: 24.31 amu

Explanation:

Magnesium isotopes      1  mass 23.99 abundance 78.99%

                                         2 mass 24.99    abundance    10.00%

                                        3  mass 25.98    abundance    11.01 %

Atomic mass of magnesium = ((23.99x0.7899) + (24.99 x 0.10) + (25.98x0.1101)

Atomic mass of magnesium = 18.95 + 2.5 + 2.86

Atomic mass of magnesium = 24.31 amu

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.