"The Scientific Methods in chemistry"

 Scientific method

Scientists find answers to questions and solutions to problems by using a method called the scientific method in chemistry. It includes:

Step 1: Make observations

Observations can be qualitative research or quantitative research. Qualitative observations describe characteristics or events in ways that do not rely on numbers. Examples of qualitative observations include the following: the outside air temperature is colder during winter, table salt is a crystalline solid, sulfur crystals are yellow, and by dissolving a penny in dilute nitric acid, blue solution, and brown gas are formed. Quantitative observations are measurements that, by definition, contain both numerical and numerical units. Examples of quantitative observations include the following: the melting point of crystalline sulfur is 115.21° Celsius and 35.9 grams of table salt—whose chemical name is sodium chloride-solve in 100 grams of water at 20° Celsius. For the dinosaur extinction question, the first observation was quantitative: Iridium concentrations in sediments from 66 million years ago were 20-160 times higher than normal.

Step 2: Formulate a hypothesis

A.    The Earth rotates on its axis every 24 hours, alternately facing the Sun on one side.

B.     The sun revolves around the earth every 24 hours.

Step 3: Design and perform experiments

After formulating a hypothesis, scientists conduct experiments to test its validity. Experiments are systematic observations or measurements, preferably conducted under controlled conditions—that is, conditions under which one variable is changed.

Step 4: Accept or modify the hypothesis

A properly designed and executed experiment enables the scientist to determine whether the original hypothesis is correct. In that case, he can go to step 5.

Step 5: Development in law and/or theory

More experimental data are then collected and analyzed, at which point a scientist may begin to think that the results are sufficiently reproducible theories in every field of chemistry.