1. 2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂
2. CH₄ + 2O₂ → CO₂ + 2H₂O
3. Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag
4. MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂
5. Pb(NO₃)₂ + 2NaCl → PbCl₂ + 2NaNO₃
1)

2)
CuSO_4+Cu_2Cl_2\neq>

The correct answer is this: THE NUCLEUS OF AN ATOM SPLITS INTO FRAGMENTS, RELEASING A LARGE AMOUNT OF ENERGY.
Nuclear fission is the process in which the nucleus of a radioactive element split into two different nucleic of smaller sizes of different elements with a large release of energy. Nuclear fission process is usually used to provide energy for electricity generation.
Answer:
C. Mole
Explanation:
Chemical formula deals with mole number
Malleablity is a physical property so hence
D. Physical property is the answer