Two scientists are cutting samples of leaves for analysis. One scientist always clips a sample from the base of the leaf near the stem, and the other scientist always clips a sample from the tip of the leaf. This illustrates a
Which practice poses the greatest safety concern?
The electron cloud model is a modern theory about the structure of atoms that explains many of the atom’s behaviors. According to the model, scientists imagine an atom to have a large nucleus of matter in the center surrounded by tiny particles called electrons. These electrons fly so fast and unpredictably around the nucleus that just one electron can appear to be a cloud. However, individual electrons are far too small for a human to see or touch.
Henry plans to monitor the change in concentration of an acid during a chemical reaction. He wants to collect data every 0.1 seconds and then to graph his data and insert it into a text document. Which pair of tools would be best for Henry to use?
The MSDS for glacial acetic acid says that it is a flammable liquid that can severely burn any human tissue it comes in contact with. It reacts with bases, various metals, and strong oxidizing agents. Its vapors can form explosive mixtures with air. Based on this information, which statement is applicable to glacial acetic acid?
In what way would a digital thermometer be preferable to those from a liquid-based thermometer?
A scientist investigated the effects of morning temperatures on flower width. Which most likely could have been a source of error in his investigation?
In an investigation that uses the scientific method, which step immediately follows asking a question?
Which example illustrates public scientific communication?
Which hypothesis could be used in a scientific experiment and possibly lead to more hypotheses and experimentation?
The MSDS for sodium hydroxide gives it a health rating of 3, a flammability rating of 0, and a reactivity rating of 1. According to the MSDS, which best describes sodium hydroxide?
Two scientists write a paper detailing their research and conclusions and submit it to a scientific journal. Several months later, the publisher sends them back the paper. Many comments from several fellow scientists are attached. Which step will the authors of the paper most likely take next?
When can a theory be modified if a new type of technology allows for new observations that raise new questions?
In 1859, Charles Darwin published the first edition of On the Origin of Species, which explained his observations of various groups of animals that showed great similarities but minor differences. Darwin concluded that if a population of one species separates into two different populations that live in separate locations, then over the course of many generations the different populations can develop into different species. This idea predicted many future biological findings and became the basis of modern biology.
What information in the MSDS would be most important to know at the end of an experiment?
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