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.
Ionization energy is the energy required to remove the
outermost electron from one mole of gaseous atom to produce 1 mole of gaseous
in to produce a charge of 1. The greater the ionization energy, the greater is
the chance f the electron to be removed from the nucleus. In this casse, Radium
has the largest ionization energy.
Answer:
D. ATP stores energy in its "tail," which is made from three phosphate groups.
Explanation:
ATP = 3 phosphates
ADP= 2 phosphates
AMP= 1 phosphate
Answer:It got to be C
Explanation: 75ml of water is
Rutherford's model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths. ... It was after this that Rutherford began developing his model of the atom.
