Trace amounts of la (lanthanum), 4 = 139, will be investigated by irradiating a 10-g soil sample in a thermal neutron aux of 10 neutrons/cm's for 14 days, and determining the induced holа. if the "la activity was found to be 10 bq 1 hour after the end of the irradiation time, calculate the la concentration in the soil in units of ug org and ppm (parts per million by weight). given: 1) la abundance - 100% (activation) - 96 tua ( la) = 1.7 days

The speed of light in a material is 0.50 c. what is the critical angle of a light ray at the interface between the material and a vacuum?

Aphysical change is a change in the size, shape,, or stafe of matter true or false

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.