Molecular mass of CaCO3 = (40+12+16*3)=100 g/mole
No. of moles= 10/100 =0.1 mole
No. Of protons in one molecule of CaCO3=(20+6+8*3)=50
No. of protons in 0.1 mole of CaCO3 will be=(0.1*50)*(6.022*10^23)
=3.011*10^24 protons