Physics
A nucleus of stable phosphorus has 15 protons and 16 neutrons.
(a) What is it's atomic number and mass number?
(b) The nucleus of radio phosphorous has one neutron more than the stable nucleus. What will be it's atomic number and mass number?
(c) What will be the atomic number and mass number of new nucleus formed by decay of a β-particle by the radio phosphorus in part (b)?
Answer
(a) Atomic number and mass number are as follows:
Atomic number = no. of protons = 15
Mass number = no. of protons + no. of neutrons = 15 + 16 = 31
(b) Atomic number = 15 and Mass number = 15 + 17 = 32
(c) Atomic number = 16 and Mass number = 32.
Explanation: After emission of β-particle, number of neutrons is decreased by one and number of protons is increased by one. So, the mass number (A) does not change whereas the atomic number (Z) increases by one.
Related Questions
A certain nucleus A (mass number 238 and atomic number 92) is radioactive and becomes a nucleus B (mass number 234 and atomic number 90) by the emission of a particle.
(a) Name the particle emitted.
(b) Explain how you arrived at your answer.
(c) State the change in the form of a reaction.
An element P disintegrates by α emission and the new element suffers two further disintegrations, both by β emission, to form an element Q. Explain the fact that P and Q are the isotopes.
1 amu is equivalent to :
- 931 eV
- 9.31 MeV
- 931 MeV
- 931 keV