The diagram shows an early version of the periodic table. The group of gases from the modern periodic table that is not represented in this table is group _. What is the missing number?

With math question will mark brainliest question in the pic.

What’s the domain of this function? fastttt

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.