Which of the following is a characteristic of the actinides? O A. They are found abundantly in nature.
B. They have a full octet of valence electrons.
C. They are all radioactive.
O D. They do not react with anything.

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.

a

yes the answer is total mass in unchanged   : )