[" (2) "quad " A "],[" CHEMISTRY "],[" Alkalimetals impart colourto Bunsen flame due "],[" (b) low innisation energy "],[" (b) their softness "],[" (d) the presence of one electron in the outer most "],[" shell "]

Assertion : Beryllium does not impart any characteristic colour to the Bunsen flame. Reason : Due to its very high ionization energy, Be requires a large amounts of energy for excitation of the electrons.

Multiple or fine structure of spectral lines is due to : (a)presence of main energy levels (b)presence of sub-levels (c)presence of electronic configuration (d)is not a characteristics of the atom

This question has Statement I and Statement II. Of the four choices given after the Statements, choose the one that best describes the two Statements. Statement - I : Beryllium does not impart any characteristic colour to the Bunsen flame. Statement - II: Due to its very high ionization energy, beryllium requires a large amount of energy for excitation of the electrons.

The electrons in a poly -electronic atom are filled one by one in roder fo increasing energy level . The enrgy fo subsgells and orientation depeds upon the values of three quantum numbers 9 i.e., n. l and m respectively derived from Schrodinger wave equation . The different orbitals fo a subsshells however possess same energy level and are called degenerater orbitals but their enrgy level charges in presenct fo magentic field and the orbitals are non-degenerate . (A) spectral line is noticed it an electron jups form one level to tohere . the paramgnetic nature of eelment sis due to the presence of unpaired electron . which element has 18 electrons in its outermost shell ?

Assertion : Berylium does not impart any characteristic colour to the Bunsen flame. Reason : Due to its very high ionization energy, beryllium requires a large amount of energy for excitation of the electrons.

which of the following statement is not correct? (A) All alkali-metals salts impart a characteristic colour to the Bunsen flame. (B) The correct order of increasing thermal stability of the carbonates of alkali metals is Li_(2)CO_(3) (C) Among the alkali metal's cesium is the most reactive. (D) The reducing character of the alkali metal hydrides follow the order: "LiH>NaH>KH>RbH>CsH" ."]

An element X from group 2 of the periodic table reacts with an element Y from group 17 to form a compound. (a) What is the nature of the compound formed? (b) Sate whether the compound formed will conduct electricity or not. (c) Give the formula of the compoumd formed. (d) What is the valency of element X ? (e) How many electrons are there in the outer most shell of an atom of element Y ?

Answer the following in one line or two: (a) what is the maximum number of electrons that can be accomodated in the outermost energy shell in an atom? (b) on the basis of thomoson's model of an atom explain how an atom is neutral as a whole (c ) how many neutons are present in hydorgen atom? (d) do isobars belongs to the same elements? e ) An element has five electons in the M shell which is the outermost shell. write its electronic configureation.

Match (A) ionisation energy, (B) atomic size, (C) electron affinity, (D) electronegativity, (E) ionisation potential with its correct definition given in (i) – (v) below. (i) The work done in removing an electron from the outermost orbit of a gaseous atom. (ii) The energy change when an atom accepts an electron in its outermost shell (iii) The energy required in removing an electron from the outermost shell of a gaseous atom (iv) The distance of the electron in the outermost orbit of an atom from its nucleus. (v) The power of the atom to attract electron or electrons in a chemical bond.