He is credited for discovering the electron
Answer:
The percent abundance of oxygen-18 is 1.9066%.
Explanation:
The average atomic mass of oxygen is given by:
Where:
m: is the atomic mass
%: is the percent abundance
Since the sum of the percent abundance of oxygen isotopes must be equal to 1, we have:
Hence, the percent abundance of O-18 is:
Hence, the percent abundance of oxygen-18 is:
Therefore, the percent abundance of oxygen-18 is 1.9066%.
I hope it helps you!
Answer 1
The sample will dissolve in more than 1 minute.
Explanation :-
Generally Solubility and rate of solubility of substances increase with the increase in temperature. So lower the temperature less fast will it dissolve in the same amount of water.
Since at 50 C it takes 1 minute to dissolve, at 20 C which is lower temperature it will take more time to dissolve.
Answer 2
Transition metals
Explanation:-
Hardness depends on the extent of metallic bonding for metals. More the number of electrons more the metallic bonding.
Alkali metals with just 1 valence electron have weak metallic bonding. Alkaline earth metals have just 2 valence electrons. Transition elements has more electrons in penultimate shell and valence shell than lanthanides. Transition metals with most metallic bonding are the hardest
The balanced skeleton reactions are given below
Cr₂O₇²⁻(aq) +3Zn(s) + 14(aq) → 3Zn²⁺(aq) +2 Cr³⁺(aq) + 7(l)
The oxidising agent and reducing agents are Cr₂O₇²⁻ and Zn.
There are following steps involve in balance redox reaction in acidic medium .
- First divide the reaction into two half reactions .
- Balance the elements other than oxygen and hydrogen atom.
- Balance the oxygen atom by adding on that side where number of oxygen atom is less .
- Balance the hydrogen atom by adding on another side of in which water attached .
- Balance the charge by adding .
- Add the two half reaction .
The species which reduces the other species in the redox reaction is called reducing agent . Similarly , the species which oxidize the other species in the redox reaction is called reducing agent .
To learn more about reducing agents please click here ,
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Answer:
Explanation:
Hello,
In this case, the first step is to compute the molarity of the first solution, for which we consider the molar mass of iron (III) nitrate that is 241.86 g/mol to compute the moles in 100.00 mL (0.1 L) of solution:
Which is actually the concentration of iron (III) ions. Therefore, for 10.00 mL of such solution, the concentration until a dilution to 250.0 mL results being:
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