Why changes of state are considered physical transition and not chemical processes

In a physical change, the chemical compontents are not altered. If ice melts into a liquid it's still water regardless; same goes if it were to vaporize and turn into a gas.

In a chemical change, the chemical components are altered. If you left a metal outside after it rained it would rust which would be a chemical process since it is chemically altered. Flamability is also a chemical process.

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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what is the average time it took the car to travel 0.25 meters?

⇒ 2.23 seconds

what is the average time it took the car to travel 0.50 meters?

⇒ 3.13 seconds