What is the half-life of a radioactive isotope?

A) the amount of time for half of a sample of the isotope to decay into a different element or isotope
B) the amount of time for half of a sample of the element to decay into nothing
C) half of the total time that the isotope has been in existence
D) half of the amount of that element in the universe
E) half of the age of the solar system


A) the amount of time for half of a sample of the isotope to decay into a different element or isotope

Physics & Space Science

You might also like to view...

Gamma rays are photons with very high energy. What is the wavelength of a gamma-ray photon with energy 7.7 × 10-13 J? (c = 3.0 × 108 m/s, h = 6.626 × 10-34 J ? s)

A) 3.1 × 10-13 m B) 3.5 × 10-13 m C) 3.9 × 10-13 m D) 2.6 × 10-13 m

Physics & Space Science

To determine the height of a flagpole, Abby throws a ball straight up and times it. She sees that the ball goes by the top of the pole after 0.50 s and then reaches the top of the pole again after a total elapsed time of 4.1 s

How high is the pole above the point where the ball was launched? (You can ignore air resistance.) A) 10 m B) 13 m C) 16 m D) 18 m E) 26 m

Physics & Space Science

A long, straight wire carrying a current is placed along the y-axis

If the direction of the current is in the +y direction, what is the direction of the magnetic field due to this wire as you view it in such a way that the current is coming directly toward you? A) clockwise, around the x-axis B) counterclockwise, around the x-axis C) counterclockwise, around the z-axis D) counterclockwise, around the y-axis E) clockwise, around the y-axis

Physics & Space Science

In the above model of an atom, where is the neutron located, assuming a neutron is present?


a. A
b. 1
c. 2
d. 3

Physics & Space Science