The alkali metals are so reactive that they are never found in nature in elemental form. Although some of their ores are abundant, isolating them from their ores is somewhat difficult. For these reasons, the group 1 elements were unknown until the early 19th century, when Sir Humphry Davy first prepared sodium (Na) and potassium (K) by passing an electric current through molten alkalis. (The ashes produced by the combustion of wood are largely composed of potassium and sodium carbonate.) Lithium (Li) was discovered 10 years later when the Swedish chemist Johan Arfwedson was studying the composition of a new Brazilian mineral. Cesium (Cs) and rubidium (Rb) were not discovered until the 1860s, when Robert Bunsen conducted a systematic search for new elements. Known to chemistry students as the inventor of the Bunsen burner, Bunsen’s spectroscopic studies of ores showed sky blue and deep red emission lines that he attributed to two new elements, Cs and Rb, respectively. Francium (Fr) is found in only trace amounts in nature, so our knowledge of its chemistry is limited. All the isotopes of Fr have very short half-lives, in contrast to the other elements in group 1.
Hey there,
Question : <span>The average, year-after-year conditions of temperature, precipitation, winds, and cloud in an area are known as its?
Answer : A, climate
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<em>~Top♥</em>
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Answer:
B the atmosphere it's not on earth and I'm pretty sure the atmosphere doesn't have water in
Explanation:
Answer:
Extensive or inextinsive and either physical or chemical
Answer:
Mechanical advantage = load/<u>effort</u>
Explanation:
Mechanical advantage is like a ratio of load to effort and many machines like pulleys depend on this relationship between load and effort for it to work.
