In 1905 Albert Einstein had proposed a solution to the problem of observations made on the behaviour of light having characteristics of both wave and particle theory. From work of Plank on emission of light from hot bodies, Einstein suggested that light is composed of tiny particles called <span>photons, </span>and each photon has energy.
Light theory branches in to the physics of <span>quantum mechanics, </span>which was conceptualised in the twentieth century. Quantum mechanics deals with behaviour of nature on the atomic scale or smaller.
As a result of quantum mechanics, this gave the proof of the dual nature of light and therefore not a contradiction.
Answer : Colloid
Explanation : Any colloid which consist of a solid evenly dispersed in a gas phase can be called as smoke. So, if smoke has to be given a matter of substance then it is can be categorized as a Colloid present in gaseous phase. Smoke is a solid which contains minute particles of dust which is homogeneously dispersed in the air.
Distance and period of time is the correct answer
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Answer:
protons are positive and neutrons are neutral, both are in nucleus
Explanation: