The correct answer among the choices is the first option. The movement of the molecules inside a block of iron when it is heated is affected by the movement being faster as compared to the first conditions. Temperature is said to be directly proportional to kinetic energy which means as temperature increases, the kinetic energy also increases. Therefore, molecules now are moving faster.
Atoms that have different numbers of neutrons than protons and electrons are called isotopes.
Answer:
I don't know the answer of this question.
