The atomic mass of an element is the average relative mass of its atoms as compared with an atom of carbon-12 whose mass is taken as 12. In terms of percentages of different isotopes, the average atomic mass can be determined as follows: $A_{average}$ = ∑( $p_{i}$ X $A_{i}$ )/100. Where, $p_{i}$ is the percentage abundance of isotope with atomic number $A_{i}$ .

So, average atomic mass of neon = $\frac{(90.51 X 19.99) + (0.27 X 20.99) + (9.22 X 21.99)}{100}$ = 20.177 amu.

3 0

3 years ago

An atom with a positive charge has ____.?

erma4kov [3.2K]

The correct answer here is A - An atom with a positive charge has more protons than electrons. In the other instances the atom would have a negative charge.

4 0

3 years ago

Cuando se quema 1 mol de metano –o sea, 16 g–, se desprenden 802

Anvisha [2.4K]

Answer:

1 gramo de metano aporta 50.125 kilojoules.

1 gramo de metano aporta 48.246 kilojoules.

Explanation:

La cantidad de energía liberada por la combustión de una unidad de masa del hidrocarburo ( $Q$ ), en kilojoules por mol, es igual a la cantidad de energía liberada por mol de compuesto ( $\bar {Q}$ ), en kilojoules por mol, dividido por su masa molar ( $M$ ), en gramos por mol: