Q2. (c) A sample of polonium-210 was left for 414 days.
After this time it had a mass of 1.45 x 10-4 g
The half-life of polonium-210 is 138 days.
Calculate the initial mass of the sample.

What is the frequency of a light wave with a wavelength of 620nm

Atotal charge of –6.50 µc is uniformly distributed within a sphere that has a radius of 0.150 m. what is the magnitude and direction of the electric field at 0.300 m from the surface of the sphere? a) 2.89 × 105 n/c, radially inward b) 6.49 × 105 n/c, radially outward c) 4.69 × 105 n/c, radially inward d) 9.38 × 105 n/c, radially outward e) 1.30 × 106 n/c, radially inward

Which of these metals are magnetic?