سؤال قراءة ستيب محلول — الفكرة الرئيسية (تدريب 5073)

(1) Scientists search for answers to questions and solutions to problems by using a procedure called the scientific method. This procedure consists of making observations, formulating hypotheses, and designing experiments, which in turn lead to additional observations, hypotheses, and experiments in repeated cycles. (2) Observations can be qualitative or quantitative. Qualitative observations describe properties or occurrences in ways that do not rely on numbers. Often, this data can be collected through observation. Examples of qualitative observations include the following: the outside air temperature is cooler during the winter season and table salt is a crystalline solid. (3) Quantitative observations are measurements, which by definition consist of both a number and a unit. Examples of quantitative observations include the following the melting point of crystalline sulfur is 115.21 degrees Celsius, and 35.9 grams of table salt whose chemical name is sodium chloride dissolve in 100 grams of water at 20 degrees Celsius. (4) After deciding to learn more about an observation or a set of observations, scientists generally begin an investigation by forming a hypothesis, a tentative explanation for the observations). The hypothesis may not be correct, but it puts the scientist's understanding of the system being studied into a form that can be tested.