<u>Answer:</u> The fraction of atom's mass contributed by nucleus is 0.99
<u>Explanation:</u>
Nucleons are defined as the sub-atomic particles which are present in the nucleus of an atom. Nucleons are protons and neutrons.
The isotopic symbol of Helium-4 atom is 
Number of electrons = 2
Number of protons = 2
Number of neutrons = 4 - 2 = 2
We are given:
Mass of He-4 atom = 
Mass of 1 electron = 
Calculating the mass contributed by the nucleus = 
Mass of the nucleus of He-4 atom = 
To calculate the fraction of atom's mass contributed by the nucleus, we use the equation:

Putting values in above equation, we get:

Hence, the fraction of atom's mass contributed by nucleus is 0.99
Answer:
45.8 mL
Explanation:
If all variables are held constant, the new volume can be found using the Boyle's Law equation. The equation looks like this:
P₁V₁ = P₂V₂
In this equation, "P₁" and "V₁" represent the initial pressure and volume. "P₂" and "V₂" represent the final pressure and volume. You can find the new volume by plugging the given values into the equation and simplifying.
P₁ = 3.1 atm P₂ = 10.5 atm
V₁ = 155 mL V₂ = ? mL
P₁V₁ = P₂V₂ <----- Boyle's Law equation
(3.1 atm)(155 mL) = (10.5 atm)V₂ <----- Insert values
480.5 = (10.5 atm)V₂ <----- Multiply 3.1 and 155
45.8 = V₂ <----- Divide both sides by 10.5
Answer:
D. Gases were released to the atmosphere
Explanation:
In accordance to the law of conservation of mass, the total amount of reactants must equate the total amount of products at the end of the reaction because matter can not be lost or created. However, certain changes like gas evolution, formation of precipitate etc. indicates the occurrence of a chemical reaction.
In a chemical reaction, the total mass of the product(s) would be less than the total weight of the reactant(s) because GASES, which constituted part of the mass of the reaction, WERE RELEASED INTO THE ATMOSPHERE. However, if the mass of the gas released can be accounted for, the amount of reactants and products must balance.
Answer:
The following three isomeric structure are given below.
Explanation:
Structure of the following three isomeric esters with chemical formula C₇H₁₂O₂
Ester #1: methyl 1-methylcyclobutanecarboxylate
Ester #2: (E)-methyl 3-methyl-3-pentenoate
Ester #3: isopropyl 2-methylpropenoate