Josh decided to mix some vinegar with baking soda. he knew that a reaction occurred because he made careful observations. he noted that the mixture started to foam up and bubble and was white in color. how did josh know that a chemical reaction occured? he was sure a reaction occurred because of

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

Argon, neon, and xenon are examples of

You've already seen the value of 9.8 in this lesson. what's this value called? what quantity does it represent?