For an unknown sample of the experiment, students measure 1679 counts when they first receive their sample and 1336 counts four minutes later. calculate the half-life t1/2of their sample.

Why should the wavelength scale of spectroscope be calibrated

First answer marked as brainiest which is the correct equation describing the first law of thermodynamics? a) when the internal energy of a system changes, it equals the amount of heat added plus the work done. b) when work is done by the piston, it is equal to the heat added plus the change in internal energy of the system. c) when heat is added to the system, it is equal to the amount of work done by the piston plus the change in internal energy of the system.

When a pendulum is held high and taut and then is released, the pendulum begins to swing. what’s the correct order of the energy transformations in this example? (pe stands for potential energy.)