Which radioactive particles can pass through paper but not through aluminium?

Answer 1

Beta is nothing but electrons. Its mass is very meagre. Its speed is higher. With all these beta can easily penetrate through the paper.

Where as the alpha is helium nucleus. Its mass is very high and so its speed is very low. Because of these, alpha cannot pass through the paper.

Answer 2

Short Answer:

Gamma rays go through most light materials, such as building materials and are effectively diminished by heavier materials such as lead. Paper and plastic wrappings do not even stop 1% of gamma radiation. What does stop depends on the energy of the gamma ray, but the amount of radiation can often be cut in half by one centimeter thickness of a heavy metal.

Specific Examples:

To a rough approximation, the mass density of the material determines how well it blocks gamma rays, not just the thickness. Lead has a density over 11 times greater than water, so one inch thickness of lead should be worth 11 inches for shielding gamma rays. In the table below, you can see lead actually does even better. The thickness necessary to reduce gamma radiation by half is listed with the density of the material in parentheses.

lead 1.0 cm (11.3 g/cm^3

steel 2.5 cm (7.86 g/cm^3

concrete 6 cm (3.33 g/cm^3

soil 9 cm (1.99 g/cm^3

water 18 cm (1 g/cm^3)

wood 302 cm (0.56 g/cm^3)

air 15000 cm (0.0012 g/cm^3)

Gamma rays can have any energy, so these numbers not equally good for all gamma rays, but work for the sort of radiation humans might encounter due to radioactivity on Earth.

See related links and related questions.

Answer 3

Beta Radiation can travel through paper. Alpha cannot travel through paper. Gamma Radiation can travel through paper Easily.

Answer 4

Beta particles (which are electrons).