Advertisements
Advertisements
Question
A certain nucleus has a mass number 20 and atomic number 9. Find the number of neutrons and protons present in it.
Solution
(i) Number of neutrons = Mass number – Atomic number
= 20 – 9 = 11
(ii) Number of protons = Atomic number = 9.
APPEARS IN
RELATED QUESTIONS
When does the nucleus of an atom tend to become radioactive?
What do you mean by Atomic mass
Radioactive substances were found to give off three types of rays. Name them. How do they
(a) React to the magnetic field?
(b) React to the electric field?
(c) Act when different thickness of lead sheets is placed in their path?
What are the uses of radioactive isotopes in following?
(a) Medical field,
(b) Agriculture,
(c) Industries?
A radioactive source emits three types of radiations.
Name the radiation which has the highest ionizing power.
State any two uses of cathode rays.
Justify with reason, whether the following nuclear reactions are allowed or not.
\[\ce{^A_Z X -> ^A_{Z - 2}X + ^4_{2}He}\]
Explain, why radium paint, consisting of zinc sulphide and a trace of radium salt, glows in the dark?
State one use of radio-isotopes.
The half-life of a radioactive nuclide is 100 hours. The fraction of original activity that will remain after 150 hours would be ______.
