must undergo addition because they have easily broken π bonds. rule states in the addition of HX to an unsymmetrical alkene, the H atom bonds to the less substituted carbon atom. are unsaturated hydrocarbons because they have fewer than the maximum number of hydrogen atoms per carbon. have good leaving groups and therefore readily undergo substitution and elimination reactions. In hydroboration, the boron atom bonds to the substituted carbon.

Alkenes, Markovnikov's, Alkenes, Alkyl halides, and less.

Explanation:

Alkenes must undergo addition because they have easily broken π bonds.

Markovnikov's rule states in the addition of HX to an unsymmetrical alkene, the H atom bonds to the less substituted carbon atom.

Alkenes are unsaturated hydrocarbons because they have fewer than the maximum number of hydrogen atoms per carbon.

Alkyl halides have good leaving groups and therefore readily undergo substitution and elimination reactions.

In hydroboration, the boron atom bonds to the less substituted carbon.

d.) circle motion requires a force to give it a centripetal acceleration.

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.