Exam 42: Nuclear Physics

Radioactive ⁹⁰Sr has a half-life of 30 years. What percent of a sample of ⁹⁰Sr will remain after 60 years?

Aluminum has atomic number 13, helium has atomic number 2, and silicon has atomic number 14. In the nuclear reaction ²⁷Al + ⁴He $\rightarrow$ ³⁰Si + ( ) the missing particle is:

Let Z denote the atomic number and A denote the mass number of a nucleus. The number of neutrons in this nucleus is:

Magnesium has atomic number 12, hydrogen has atomic number 1, and helium has atomic number 2. In the nuclear reaction ²⁴Mg + ²H $\rightarrow$ ( ) + ⁴He the missing quantity is:

The graph shows the activity R as a function of the time t for three radioactive samples. Rank the samples according to their half-lives, shortest to longest.

The smallest particle of any chemical element that can exist by itself and yet retain the qualities that distinguish it as that element is:

A femtometer is:

²¹⁰Bi (an isotope of bismuth) has a half-life of 5.0 days. The time for three-quarters of a sample of ²¹⁰Bi to decay is:

Volumes of atomic nuclei are proportional to:

At the end of 14 min, 1/16 of a sample of radioactive polonium remains. The corresponding half-life is:

A proton in a large nucleus:

Of the three common types of radiation (alpha, beta, gamma) from radioactive sources, electric charge is carried by:

The isotopes of an element:

Some alpha emitters have longer half-lives than others because:

Bromine, with atomic mass 79.942 u, is composed of nearly equal amounts of two isotopes, one of which contains 79 nucleons per atom. The mass number of the other isotope is:

A nucleus with a mass number of 64 has a mean radius of about:

The mass of a neutron:

Starting with a sample of pure ⁶⁶Cu, 7/8 of it decays into Zn in 15 minutes. The corresponding half-life is:

The atomic number of an element is:

A radium atom, ²²⁶Ra (Z = 86), emits an alpha particle. The number of protons in the resulting atom is: