Consider an arbitrary radionuclide X (τ = 30 min), which decays to the stable nuclide Y through β− decay. If a sample contains 2 pmol1 of X, what is the activity of this sample? If the sample were allowed to stand for a period of 7 hours, what would be its activity?

the aurora is formed when charged particles emitted from the sun during a solar flare penetrate the earth's magnetic shield and collide with atoms and molecules in our atmosphere. these collisions result in countless little bursts of light, called photons, which make up the aurora.

auroras are generated by charged solar particles hitting molecules in earth's atmosphere. this usually happens in high latitudes, because our planet’s magnetic field tends to funnel these particles toward the poles. that’s why it can be experienced in northern ohio.

could you add the photo?

explanation: