Elijah performed an experiment to explore the differences between chemical and physical changes. In which trial did Elijah observe the formation of new substances with different properties

An atom of lithium-7 has an equal number of(1) electrons and neutrons(2) electrons and protons(3) positrons and neutrons(4) positrons and protons

Which statement is true about this reaction? 14n+1h 15o it is a practical source of energy on earth. it occurs only outside the solar system. its product is heavier than each of its reactants. it shows the critical mass of an element.

Which statement best describes what happens when molecular compounds melt