How are atoms formed?

atoms were created after the Big Bang 13.7 billion years ago. As the hot, dense new universe cooled, conditions became suitable for quarks and electrons to form. Quarks came together to form protons and neutrons, and these particles combined into nuclei.

Explanation:i hope that helps

fe 55.85 g/mol and h2o 18.02 g/mol.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.