According to the periodic table of elements, calcium (ca) has: a- 20 protons and 20 electrons b- 40.08 protons c-20 protons and 20.08 electrons d-20 protons and zero electrons

Suppose that recording station n is located 200 km north of the epicenter of an earthquake, and recording station s is located 100 km south of the epicenter of the same earthquake. which of the following statements would be true?

Diamond will scratch quartz. true or false

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.