If a radioactive element is placed in an evacuated container, its rate of disintegration

The rate of disintegration of a radioactive element at any instant is 10^3 dps. If the half-life of that element is 1 second, then what is its rate of disintegration after 1 second and after 3 second?

When a radioactive substance is subjected to a vacuum, the rate of disintegration per second

Rate Of Radioactive Disintegration

With time, the rate of radioactive disintegration :

What parts of a radioactive element is disintegrated in its average life period?