Mass of an individual atoms or molecules
You make them strong for example if you rub a balloon in your hair the longer you do it the longer it sticks because of static
Answer:
Option (c) is correct.
Explanation:
Acceleration of an object is given by the formula as follows :

Where
u and v are initial and final velocity
t is time
(v-u) is also called the change in velocity
So, the acceleration of an object is equal to the rate of change of velocity. Hence, the correct option is (c) " Change in its velocity divided by the change in time".
Using physical means such as electrostatic filters or mechanical filters :)
Answer:
the ratio of the kinetic energy of an electron to that of a proton if their wavelengths are equal is 1835.16 .
Explanation:
We know, wavelength is expressed in terms of Kinetic Energy by :

Therefore , 
It is given that both electron and proton have same wavelength.
Therefore,
.... equation 1.
.... equation 2.
Now, dividing equation 1 by 2 .
We get ,

Putting value of mass of electron =
and mass of proton = 
We get :

Hence , this is the required solution.