Carbon 13 I believe.
Never heard of an isotope for boron or nitrogen and I know Carbon 12 is the original form of carbon so.. Yeah
Hey There!:
The density is the quotient between the mass of a material and the volume occupied by it, The density can be expressed for a substance or for a mixture of substances. For example, water density in ambient conditions is equal to 1.00 g/cm3, which means that in 1 cm³ or 1 mL, there are 1.0 g of water. Therefore:
D = m / V
D = 20 g / 5 mL
D = 4,0 g/mL
hope that helps!
I believe the answer is "After adding two substances together a new order is detected" because nearly all of the other answers suggest a chemical change has taken place. The reason I say "almost" is because answer two and four results in bubbles forming so the answer cannot be both. The only one to not clearly show a chemical change has occurred is the last answer.