Which have about the same mass?

Question

Which have about the same mass??  
A. Protons and neutrons  
B. Neutrons and electrons  
C. Electrons and alpha particles  
D. Neutrons and beta particles

Accepted Answer

Correct Answer: (A)Protons and neutrons. 
Rationale: Protons and neutrons have about the same mass.Subatomic particles differ greatly in mass, but two of them are nearly equal. Protons and neutrons are both nucleons located in the atomic nucleus, and their masses are almost identical. Each has a mass close to 1 atomic mass unit (u), which is why atomic mass is largely determined by the number of protons and neutrons rather than electrons.A. Protons and neutronsA proton has a mass of about 1.007 u, and a neutron has a mass of about 1.009 u. The difference between them is extremely small, so for most chemical and biological purposes, they are considered to have the same mass.B. Neutrons and electronsElectrons are much lighter than neutrons. An electron has a mass of about 1/1836 that of a proton or neutron, making the difference very large.C. Electrons and alpha particlesAn alpha particle consists of two protons and two neutrons, giving it a mass of about 4 atomic mass units. An electron’s mass is negligible in comparison.D. Neutrons and beta particlesA beta particle is essentially an electron (or positron) emitted during radioactive decay. As with electrons in general, beta particles are far lighter than neutrons.ConclusionAmong common subatomic particles, protons and neutrons are unique in having nearly identical masses. Their similar mass explains why they together account for almost all of an atom’s mass, making option A the correct choice.

Which have about the same mass?

A
Protons and neutrons

B
Neutrons and electrons

C
Electrons and alpha particles

D
Neutrons and beta particles

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Related Questions

Which have about the same mass?

A Protons and neutrons B Neutrons and electrons C Electrons and alpha particles D Neutrons and beta particles

Topic Flashcards

Mini Quiz

Related Questions

A
Protons and neutrons

B
Neutrons and electrons

C
Electrons and alpha particles

D
Neutrons and beta particles