A covalent bond where electrons are attracted evenly to both ions: A: Nonpolar covalent bond

B: Polar covalent bond

Explanation:

This type of a covalent bond where electrons are shared equally between two atoms is called a non-polar covalent bond. ... Covalent bonds where electrons are not shared equally between two atoms are called polar covalent bond.

the maximum mass of nh3 is nh3 in grams

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.