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.
Answer:The oxygen during photosynthesis comes from split water molecules. During photosynthesis, the plant absorbs water and carbon dioxide. After the absorption, the water molecules are disassembled and converted into sugar and oxygen.
Probably life science or biology.
Answer:
6L
Explanation:
<em>if it's 3L per 200kPa</em>
then it would be;
4L per 300kPa
5L per 400kPa
6L per 500kPa
that's how i'd work it out in my head, hope it helps, but not sure though!
Answer:
![CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 CHO + 2[Ag(NH_3)_2]+ 3 H_2 O](https://tex.z-dn.net/?f=CH_3%20CH_2%20CH_2%20CH_2%20CH_2%20CH_2%20CHO%20%2B%202%5BAg%28NH_3%29_2%5D%2B%20%203%20H_2%20O)
= 
Explanation:
Tollens test is carried out to perceive difference between aldehydes and ketones on the basis of their capability to oxidized easily.
when Tollens react with aldehyde (heptanal) , a silver mirror is form on inner side of container.
The reaction between tollens and heptanal is given as
![CH_3 CH_2 CH_2 CH_2 CH_2 CH_2 CHO + 2[Ag(NH_3)_2]+ 3 H_2 O](https://tex.z-dn.net/?f=CH_3%20CH_2%20CH_2%20CH_2%20CH_2%20CH_2%20CHO%20%2B%202%5BAg%28NH_3%29_2%5D%2B%203%20H_2%20O)
= 
