Naturally occurring boron is composed of two isotopes. The percent abundance and the mass of each isotope are listed below: 19.9% of ne boron atoms have a mass of 10.013 amu and 80.1% of the boron atoms have a mass of 11.009 amu.
calculate the average atomic mass of boron, you would set up the following calculation:
What

1. they vary with a higher number because boiling is way hotter than melting

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

it would be b. 6co2 + 6h2o --> c6h12o6 + 6o2