Answer:
A. there is an isotope of lanthanum with an atomic mass of 138.9
Explanation:
By knowing the different atomic masses of both Lanthanum atoms, we can not tell anything about their occurence in nature. Therefore, all the last three options are incorrect. Because, the atomic mass does not tell anything about the availability or natural abundance of an element.
Now, the isotopes of an element are those elements, which have same number of electrons and protons as the original element, but different number of neutrons. Therefore, they have same atomic number but, different atomic weight or atomic masses.
Hence, by looking at an elements having same atomic number, but different atomic masses, we can identify them as isotopes.
Thus, the correct option is:
<u>A. there is an isotope of lanthanum with an atomic mass of 138.9.</u>
1. mol ratio of Al(NO₃)₃ : Na₂CO₃ = 2 : 3
2. Na₂CO₃ as a limiting reactant
<h3>Further explanation</h3>
Given
Reaction
2 Al(NO₃)₃ + 3 Na₂CO₃ → Al₂(CO₃)₃ + 6 NaNO₃
Required
mol ratio
Limiting reactant
Solution
The reaction coefficient in the chemical equation shows the mole ratio of the components of the compound involved in the reaction (reactants and products)
1. From the equation mol ratio of Al(NO₃)₃ : Na₂CO₃ = 2 : 3
2. mol : coefficient of Al(NO₃)₃ : Na₂CO₃ = 2 mole/2 : 2 mole/3 = 1 : 0.67
Na₂CO₃ as a limiting reactant (smaller)
Answer:
well try talking to him first and being his friend. introduce yourself and try not to be too awkward or shy. can't reltate lol. after that if he really likes you, he'll initiate stuffs ^^
Explanation:
It is a global issue that is impacting WA’s water supply and our way of life. The impacts are felt across the world, Australia, and throughout WA in our communities, businesses, farms and homes.
