If the electrons in a collection of hydrogen atoms are raised to the n = 6 excited state, how many different wavelengths of light will be emitted as the atoms relax to their ground state? (a) 16 (b) 15 (c) 12 (d) 10 (e) 1

(e) 1

Explanation:

Each atom has some energy levels and each energy level requires an electron to have certain amount of energy to reside in that energy level. Similarly, in order to excite the hydrogen atoms to a state n =6, its electrons must be provided a certain amount of energy that is constant. This energy is provided in form of photons. These photons have a constant wavelength as a result of constant energy. So, when these electrons go back to the ground state, they emit photons of same wavelength to release the energy they absorbed. Hence, only 1 wavelength is produced when atoms relax to their ground state from n = 6.

Therefore, the correct answer will be:

(e) 1  

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.