Plzz help me fast (There is both physics and chemistry question )

1) Write the molecular formula of the following by crisscross method :
1. Potassium sulphate
2. Sodium chloride
3. Ammonium chloride
4. Silver oxide

2) Prove that F=ma pl

Which lists the fundamental forces in order, from strongest to weakest? strong nuclear, weak nuclear, electromagnetic, gravitational strong nuclear, electromagnetic, weak nuclear, gravitational gravitational, weak nuclear, electromagnetic, strong nuclear electromagnetic, gravitational, strong nuclear, weak nuclear