Modern physics

Question 1 of 10

When ²³⁸U emits an alpha particle, its mass number becomes

Question 2 of 10

The half-life of a radioactive sample is 5 days. What fraction of it remains after 15 days?

Question 3 of 10

When a nucleus emits an alpha particle, its mass number

Question 4 of 10

A Geiger–Müller tube is used to

Question 5 of 10

²²⁶₈₈Ra decays by α emission. The daughter nucleus is

Question 6 of 10

An alpha particle is the same as a

Question 7 of 10

A radioactive sample has an activity of 800 counts/min. After two half-lives the activity is

Question 8 of 10

The half-life of a sample is 2 days. The fraction left after 6 days is

Question 9 of 10

The work function of a metal is 2.0 eV. Light of photon energy 3.5 eV falls on it. The maximum kinetic energy of the electrons is

Question 10 of 10

Alpha particles are