The result is 0.14303691.
Carbon-13 (¹³C) is a stable isotope of carbon with a mass number of 13, composed of six protons and seven neutrons.
Isotopes are elements that share the same atomic number but have different mass numbers, meaning they have a varying number of neutrons.
ω(¹³C) = 1.10% ÷ 100%.
ω(¹³C) = 0.0110; this indicates the natural abundance of carbon-13.
m(¹³C) = 13.003355; the atomic mass assigned to carbon-13.
ω(¹³C) · m(¹³C) = 0.0110 · 13.003355.
ω(¹³C) · m(¹³C) = 0.14303691.
The element you are looking for is Pb (Lead). Just check the last orbital on the periodic table to find it!
Response:
4.5 m³
Resolution:
The statement indicates the presence of two blocks on a lid of a container with a volume of 9 m³. The lid's weight is equal to that of the two blocks. Thus, there were initially four blocks (or 4 atm pressure) acting on a volume of 9 m³.
After adding four additional blocks on the lid, the pressure rises from 4 atm to 8 atm (2 atm from the lid, 2 atm from the original blocks, and 4 atm from the new blocks).
Hence, The data established is,
P₁ = 4 atm
V₁ = 9 m³
P₂ = 8 atm
V₂ =?
Using Boyle's Law,
P₁ V₁ = P₂ V₂
Resolving for V₂,
V₂ = P₁ V₁ / P₂
Substituting values yields:
V₂ = (4 atm × 9 m³) ÷ 8 atm
V₂ = 4.5 m³
Answer:
Explanation:
Diethyl malonate possesses greater acidity compared to monocarbonyl substances (pKa=13) because its alpha hydrogens are linked to two carbonyl groups. Consequently, the malonic ester can be readily changed into its enolate ion by reacting it with sodium ethoxide in ethanol. When the malonic ester undergoes alkylation, a hydrogen atom in the alpha position becomes acidic, permitting another round of alkylation to yield a dialkylated malonic ester.
In this scenario, when diethyl malonate interacts with urea in the presence of sodium ethoxide base, the second alkylation step occurs within the molecule, producing a cyclic compound known as barbituric acid.
The atomic number of the element indicated by the model is 8, corresponding to option 'C' in the question.