Calculate the frequency of 8.0 meters long and 345 m/s

What are the phases shown in a and d called?

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. this process was repeated by 3 observers. the pooled standard deviations of these 3 data sets was 1.21. determine the true mean force using all pooled data (with a 95% probability). the result should look like this: true mean = mean +/- margin of error

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.