How many elements are present in each of the following HF and. Hf ii) Co and CO iii) Si and SiO2 iv) PoCl2 and POCC3

HF and Hf consist of 3 elements: Hydrogen (H), Flourine (F) and Hafnium (Hf).Co and CO consist of 3 elements: Cobalt (CO), Carbon (C) and Oxygen (O).Si and SiO2 consist of 2 elements: Silicon (Si) and Oxygen (O). {unless you mean SI where "I" would be iodine)PoCl2 and POCC3 have 5 elements: Polonium (Po), Chlorine (Cl), Phosphorus (P), Oxygen (O) and Carbon (C).

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