Sodium (Na) is very reactive because it does not have a full valence shell.
Answer:

Explanation:
= Permittivity of free space = 
= Surface charge density = 
= 0.57-0.26
q = Charge = 
m = Mass of object = 
Electric field due to a sheet is given by

Electric field is given by

Voltage is given by

Kinetic energy is given by


The initial speed of the object is 
The temperature will increase
The frequency of a simple harmonic oscillator such as a spring-mass system is given by

where
k is the spring constant
m is the mass attached to the spring.
Re-arranging the formula, we get:

and since we know the constant of the spring:

and the frequency of oscillation:
f=1.00 Hz
we can find the value of the mass attached to it: