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

In order to do work, the force vector must be question 1 options: in a different direction than the acceleration vector. in a different direction than the displacement vector. in the same direction as the displacement vector and the motion. in the same direction as the acceleration vector.

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b.b. at twice the distance, the magnitude of the field is 2b.c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.

Awave has a wavelength of 7 mm and a frequency of 19 hertz. what is its speed?