Moles of ca3(po4)2 = 23.7 / 310.17 = 0.076
moles of (PO4)3- = 0.076 x 2 = 0.152
now, no. of ions = 0.152 x 6.022 x 10^{23}
= 9.2 x 10^{22}
Answer:
Rust is a chemical reaction (oxidation) of iron that occurs over a period of time as the bare metal surface comes in contact with oxygen present in the air or water. Rust "eats" away the metal, rendering it weak and fragile. ... Avoid contact with water or moisture.