At what point is the half-life of a radioactive isotope reached? A. When half the parent nuclei in a sample have become daughter nuclei
B. When all the daughter nuclei in a sample have become parent nuclei
C. When half the daughter nuclei in a sample have become parent nuclei
D. When all the parent nuclei in a sample have become daughter nuclei

Imagine you had to physically add electrons, one at a time, to a previously neutral conductor. you add one electron very easily, but the second electron requires more work. in your initial post to the discussion, explain why this is. also, what happens to the work needed to add the third, fourth, fifth, and subsequent electrons

Directions: count the number of atoms. ar co2 na3po4 so3 nac2h3o2

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.