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 correct answer would be the third choice.
Homo-genesis mixtures are the same in composure, and will be hard to break apart other then with chemical means.
Hope this helps!
Answer:
The molecular equation for the reaction betweensodium carbonate and sulfuric acid is: 1. Na2CO3(aq)+H2SO4(aq)→Na2SO4(aq)+CO2(g)+H2O(l) N a 2 C O 3 ( a q ) + H 2 S O 4 ( a q ) → N a 2 S O 4 ( a q ) + C O 2 ( g ) + H 2 O ( l ) .
Explanation:
The daughter isotope (a decay product)of O-15 = N-15(Nitrogen 15)
<h3>Further explanation
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Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
- alpha α particles ₂He⁴
- beta β ₋₁e⁰ particles
- gamma particles γ
- positron particles ₁e⁰
O-15 emits positron particles ₁e⁰, so the atomic number decreases by 1, the mass number is the same
Reaction
The mass number of the daughter isotope = 15, atomic number = 7
If we look at the periodic system, the element with atomic number 7 is Nitrogen (N)
