3. Which of the following transition metals is a component of vitamin B₁₂?(A)Co(B)Zn(C)Fe(D)Au(E)Cu

10. Which property distinguishes inorganic nanoparticles from their bulk counterparts?(A)Increased solubility in polar solvents(B)Reduced surface area to volume ratio(C)Enhanced reactivity due to decreased surface area(D)Altered optical, electronic, or magnetic properties at the nanoscale(E)Lower sensitivity to environmental factors compared to bulk materials