What is the answer to this I need help please

Answer : The boron-11 isotope is the most abundant.

Explanation :

As we are given that:

Average atomic mass of boron = 10.81 amu

Mass of boron-10 = 10.0129 amu

Mass of boron-11 = 11.0093 amu

As we know that the average atomic mass of an element is always closest to the most abundant isotope.

Out of the two boron isotopes, B-11 is closest in mass to the weighted average. Therefore, it is the most abundant.

Hence, the boron-11 isotope is the most abundant.

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.