Answer:
A is the answer. Ca(calcium) is an element, O2 is a diatomic element, and NaCl is a compound composed of Na(sodium) and Cl(chlorine)
Explanation:
hopefully that helps!!!
A wave with a smaller wavelength has more energy than one with a larger wavelength.
B that’s is not a chemical change because I took the test
To convert Celsius into kelvin add 273 to o celsius.o+273=273k
Description: The standard enthalpy of reaction is the enthalpy change that occurs in a system when matter is transformed by a given chemical reaction, when all reactants and products are in their standard states.