There are two naturally occurring isotopes of boron determine the abundance of each isotope

Answer : The correct answer is:

The abundance of isotopes can be found out using following formula :

atomic mass of element = ( abundance of isotope 1 * mass of isotope 1 ) + ( abundance of isotope 2 * mass of isotope 2 ) +

Boron ( mass = 10.811 u ) has two isotopes : ¹⁰B ( mass = 10.0129 u ) and ¹¹ B ( mass = 11.0093 u )

Sum of abundance of all isotopes = 100%

Lets assume abundance of isotope ¹¹B = x % = 0.01 x , so abundance of isotope ¹⁰B = 100 % - x% = 100/100 - x/100 = 1 - 0.01 x

Plugging values in formula :

10.811 = ( 0.01 x * 11.0093) + [( 1 - 0.01 x) * 10.0129 ]

10.811 = (0.110093 x ) + ( 10.0129 - 0.100129 x )

10.811 - 10.0129 = 0.110093 x - 0.100129 x

0.7981 = 0.009964 x

Dividing both side by 0.00964

0.7981 / 0.009964 = 0.00964 /0.00964 x

x = 82.7 %

Abundance of of isotope ¹¹ B = 82.7 %

Abundance of isotope ¹⁰ B = 100% - x % = 100 %- 82.7 % = 17.3 %

b..

is the correct one

explanation:

covalent bonds form as valence electrons are shared between two atoms. lewis structures and structural formulas are common ways of showing the covalent bonding in organic molecules. formal charge describes the changes in the number of valence electrons as an atom becomes bonded into a molecule.

the answer is c

tell me if wrong