All of the following are physical properties of hydrogen peroxide except it a. is a liquid b. reacts with sunlight c. has no color d. has a density of 1.44 grams per cubic centimeter

The answer to this question is B, Reacts with sunlight.

The 2 main properties of substances are their physical properties and chemical properties. 
Physical properties are some observable/measurable characteristics, such as their color, mass, state, melting point, conductivity etc.

Meanwhile, for chemical properties, they're about how the substance reacts with other substances, such as metals react with acid to form hydrogen. And by the word "react", it means there's no way turn the reaction product back to the original substance without using chemical methods such as heating or electrolysis. 

Therefore, all the choices above are physical properties of hydrogen peroxide except for B, as it is the only choice that relates to the substance reacting to another substance. 

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.