Question

Which of the following statements is false?
A. Neutrons have the highest mass among the fundamental particles
B. The mass of an electron is negligible
C. The value of e/m is the highest for a proton
D. The charge of the neutron is zero

Answer 1

As we know atoms has 35 subatomic particles, but electrons, protons, and neutrons are the fundamental particles. These are the building blocks of an atom.

Complete step by step answer:
If we talk about the mass of the fundamental particles, the mass of the electron is 0.0005486 u and the mass of proton and neutron are 1.007276 u and 1.008665 u respectively. As we see the mass of a neutron is slightly greater than the mass of a proton. And the mass of the proton is greater than the mass of the electron. So we can say the mass of neutrons is highest among the fundamental particles hence the statement in option A is correct.
If we talk about the mass of electron it is 1/1837 times the mass of protons which is quantitatively equal to $9.11 \times {10^{ - 28}}$g which is a very small quantity, hence we can say the mass of an electron is negligible. Hence option B is also a correct statement.
In case of the charge of fundamental particles, a proton is a positive charge particle and the electron is a negative charge particle since the atom is electrically neutral so the charge on the neutron is zero. It is a neutral particle. Hence this is also a correct statement.
If we talk about e/m i.e. charge by mass ratio, the value of charge by the mass ratio of the electron is 1837 times the value of charge by mass ratio of proton. So, we can say the charge by mass ratio for protons is not the highest. Hence this statement about e/m ratio is false.

So, the correct answer is Option C .

Note:
We can use charge by mass ratio of electron to calculate its mass as given below:
The value of charge by mass ratio is $- 1.76 \times {10^{ - 19}}$ coulomb/g
And the charge on an electron is $- 1.602 \times {10^8}$ coulomb
Hence the mass of the electron
$\dfrac{e}{{e/m}} = \dfrac{{1.602 \times {{10}^{ - 19}}}}{{1.76 \times {{10}^8}}} \\\ \Rightarrow 9.102 \times {10^{ - 28}}g \\\$