Hydrogen has four emission lines in the visible light range : violet, blue, green, and red. match the color of the emission line to its electron transition.

a. n =  4     →   n =  2 
b. n =  3     →   n =  2
c. n =  6    →   n =  2
d. n =  5    →   n =  2 

C.    n = 6   →   n = 2     Violet

D.    n = 5   →   n = 2     Blue

A.    n = 4   →   n = 2     Green

B.    n = 3   →   n = 2     Red

Explanation:

The transitions involved are all to energy level n=2  from higher energy levels. The energy of the emission line correspondingly will reflect a higher energy the greater n is and the color of the emission spectra line will likewise correspond to higher energy. Since the energy of the colors given  follow the sequence:

Remember that the the energy and the frequency of the visible colors is greatest for violet and lowest for red. That is why we refer  to ultraviolet light being highly energetic ( sunburn) and infrared gogles which are used for low energy night vision ( the ultra and infra mean beyond visible spectrum)

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml

c. electrical charges of ionic bonds.