Answer:
A) The number of atoms in a grain of iron is most similar to the number of meters between Earth and Vega.
The options attached to the question are missing, but out of the numbers presented in the options, 10¹⁷ is closest to 10¹⁸.
B) The mass of a grain of iron is approximately (9 × 10⁻⁵) g
Explanation:
The options attached to the question are missing, after searching online, the image of the question was obtained, but it won't be attached to this solution in order not to violate the community guidelines and lead to deletion of answer.
But, out of the numbers presented in the options, 10¹⁷ is closest to 10¹⁸, hence, the number of atoms in a grain of iron is most similar to the number of meters between Earth and Vega.
The second part of the question asks for the approximate mass of a grain of iron.
1 atom of iron has a mass of (9 × 10⁻²³) g
1 grain of iron has about (1 × 10¹⁸) atoms of iron.
So, the mass of a grain of iron = (9 × 10⁻²³) × (1 × 10¹⁸) = (9 × 10⁻⁵) g
Hope this Helps!!!
Answer:
+4
Explanation:
In PbO2, oxygen exhibits an oxidation number of -2 (since it's not a peroxide or superoxide):
Let the oxidation number of Pb be x. Then, for the compound to be neutral, the oxidation numbers of all atoms should add up to zero.
⇒ x + (−2) + (−2) = 0
x = +4
So the oxidation no. of Pb is +4.
I hope this helps.
Answer:
The rate would be lower and the concentration of reactants would be lower.
Explanation:
The rate of a chemical reaction depends on the rate constant and the concentration of reactants.
For Ex:
For a reaction experimentally given by A + B ----> C + D
Rate = k[A][B]
where k is the rate constant
[A] = concentration of reactant A
[B] = concentration of reactant B
As the reaction proceeds,the concentration of reactant decrease and concentration of products increase.Rate constant k depends only on temperature and activation energy.Hence it will remain constant throughout the reaction assuming that reaction is carried out at constant temperature and pressure.
Hence rate will depend only on concentration of reactants and hence decrease with decrease in concentration of reactants.
D because that’s the only one that makes sense
The final volume reading on the graduated cylinder is 12.52ml
Density = mass / volume
Volume = mass / density
Volume of zinc = 2.83/7.14
Volume of zinc = 0.3963
Initial volume = 12.13 ml
Total volume = initial volume+ volume of zinc
Total volume = 12.13 + 0.3963
Total volume = 12.5263 = 12.52 ml
To know more about volume to go the given link :
brainly.com/question/11510153
