Why does sodium chloride form a crystal lattice

Fill in the coefficients that will balance the following reaction: a0cr2(so4)3 + a1agno3 -> a2cr(no3)3 + a3ag2so4

Apiece of copper has a temperature of 75.6 0c. when the metal is placed in 100.0 grams of water at 19.1 0c, the temperature rises by 5.5 0c. what is the mass of the metal?

Given the following information: mass of proton = 1.00728 amu mass of neutron = 1.00866 amu mass of electron = 5.486 × 10^-4 amu speed of light = 2.9979 × 10^8 m/s calculate the nuclear binding energy (absolute value) of 3li^6. which has an atomic mass of 6.015126 amu. j/mol.