At the core of biology and other sciences lies a problem-solving approach called the scientific method. 1  Make an observation. 2  Ask a question. 3  Form a hypothesis, or testable explanation. 4  Make a prediction based on the hypothesis.  Test the prediction.
Xi. Xi is the 14th letter of the Greek alphabet. It is pronounced in Modern Greek, and generally or in English. In the system of Greek numerals, it has a value of 60. Xi was derived from the Phoenician letter samekh. Xi is not to be confused with the letter chi, which gave its form to the Latin letter X.
The name for the 14th letter of Classical and Modern Greek. The 15th in Ancient and Old Greek. xi (Noun). Either of a pair of hyperons having spin 1/2, which decay into a lambda particle and a pion.