The photoelectron spectra of the 1s electrons of two isoelectronic species, Ca2+ and Ar, are shown above. Which of the following correctly identifies the species associated with peak X and provides a valid justification? Please help.

do u have any choices to choose from ? ?

the major pests we deal with are insects, weeds and fungal diseases. a pesticide is a product, whether organic or chemical, used to kill the target pest. there are other techniques gardeners should use that can prevent the severe infestations that make the use of pesticides necessary

there is none because earth is stationary and flat.

answer: i dont know the answer but this might

explanation:

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