Calculate the mass of 1.35 moles of sodium chloride (NaCl). a.43.29 g NaCl

b.1.35 g NaCl

c.78.897 g NaCl

d.58.442 g NaCl

need quick

Which of these is constant for all types of electromagnetic radiation in a vacuum? select one: a. wavelength b. frequency c. photon energy d. amplitude e. velocity

Aresistor with an unknown resistance is connected in parallel to a 9 ω resistor. when both resistors are connected in parallel to an emf source of 21 v, the current through the unknown resistor is measured with an ammeter to be 4 a. what is the resistance of the unknown resistor? answer in units of ω.

Calculate a pendulums frequency of oscillation (in hz) if the pendulum completes one cycle in 0.5s.