It'd be a physical change. This is because it's a change in the state of matter and not altering the chemical structure of water
CuCl2 + 2NaNO3 ----> Cu(NO3)2 + 2NaCl
using molar masses:-
Theoretical yields:-
63.54 + 2(35.45) g of CuCl2 produces 2(22.98 + 35.45) g of NaCl
134.44 g .................................................... 116.86 g
31.0 g ....................................................31.0 * 116.86 /134.44=26.95g
So percentage yield is 21.2* 100 / 26.95 = 78.7% to nearest tenth
(sample g/1) X (1 mole/40.078(MW of Ca)) = moles of sample (moles of sample)(6.022 x 10^23( no of atoms)/ 1 mole) = # of atoms in a 120 g sample of calcium Avogadro's number=6.022x 10^23 atoms in 1 mole
Many atoms if they are radioactive isotopes will loss protons and neutrons as radiation in order to gain and become more stable
hope that helps
Amorphous is the answer. A glass is an amorphous solid.