With 1-4. urgent need on physics questions. 100% correct answers

1).  Speed of any wave = (wavelength) x (frequency) .  I got 4.5 m/s in my head, but you need to check this.

2).  and  3).  are marked correctly

4).  Transverse waves have crests and troughs.  But sound waves are longitudinal waves, so they don't have any.  The wavelength of a sound wave is the distance between consecutive centers of compression (or rarefaction).

number of electrons for neutral cl

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force