Answer: 12.18 u
Explanation: The average atomic mass of an element is calculated by taking the weighted average of the atomic masses of its stable isotopes.
In other words, each stable isotope will contribute to the average mass of the element proportionally to its abundance.
Answer:

Explanation:
Hola,
En este caso, podemos usar la ley de Boyle, la cual nos permite analizar el comportamiento volumen-presión en un gas ideal de manera inversamente propocional:

Así, dado el volumen y la presión inicial, la cual se convierte a atmósferas (760 torr = 1atm), calculamos el volumen final a 1 atm como se muestra a continuación:

Saludos!
Answer:
Read Explanation
Explanation:
Aluminum foil does contain billions of atoms, but we write them just as Al because aluminum does not exist in single atom forms in normal circumstances but as billions in metallic bonds.
Correct Question: what is the oxidizing agent in the reaction.
2MnO4–(aq) +10Cl–(aq) + 16H+(aq) --------> 5Cl2(g) + 2Mn2+(aq) +8H2O(l)
Answer: MnO4-is the oxidizing agent
Explanation:
In the reaction 2MnO4–(aq) +10Cl–(aq) + 16H+(aq) --------> 5Cl2(g) + 2Mn2+(aq) +8H2O(l)
Oxidizing agent oxidizes other molecules while the themselves get reduced.
oxidizing agents give away Oxygen to other compounds.
MnO4-is the oxidizing agent because
On the reactants side
Oxidation number of Mn in 2MnO4- is +7
Oxidation number of Cl- is -1
On the products side
Oxidation number of Mn is +2
While oxidation number of Cl is zero
Therefore the oxidizing agent is 2MnO4 because is oxidizes Chlorine from -1 to 0 while itself got reduced from oxidation state of +7 to +2