A test charge experiences a force of 1.66 ×10−9 N at a point where the electric field intensity is exactly 0.000347 N/C. Which value best represents the size of the test charge?

A. 5.76 x 10-13 C
B. 4.78 x 10-6 C
C. 4730 C
D. 56700 C

This is how zirconium appears in the periodic table. rounded to the nearest whole number, how many electrons are in an atom of zirconium?

If an atom contains 11 protons in its nucleus, predict the element with the atomic number and electronic configuration. will the number of electrons remain the same during the chemical reaction in such an atom? explain.

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)