As scientists have learned more than atoms, models of atoms have changed. One of the first atomic models was a solid ball, such as a marble. What are two limitations of using a marble to model an atom?

The model dose not move or behave like a real atom.

The model dose not show the true size of an atom.

Explanation:

I had this quiz

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.