Asample of sodium-22 (z= 11) decays to neon-22 (z 10). the alf-life of this sodium isotope is 2.5 years. the masses of the sodium-22 and neon- 22 atoms are 21.994434 u and 21.991383 u, respectively. the initial mass of the sodium-22 sample is 5 mg. [2 points] what is the radius of the sodium-22 nucleus?

The least penetrating form of radiation is

Two 1.20-m nonconducting wires meet at a right angle. one segment carries + 2.50 µc of charge distributed uniformly along its length, and the other carries - 2.50 µc distributed uniformly along it, as shown in fig. 21.50. ( a. find the magnitude and direction of the electric field these wires produce at point p, which is 60.0 cm from each wire. ( b. if an electron is released at p, what are the magnitude and direction of the net force that these wires exert on it?

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?