Monica found a clear mineral crystal. she wanted to identify its hardness. she tried to scratch it with her fingernail, a penny, and a steel nail but none of those worked. then she tried topaz, which did leave a scratch . the mineral was able to scratch glass. what mineral could monica have found? explain your answer.

yea hi

explanation:

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).

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.