Answer:
From the image the answer is 24.
Answer:
Valence electrons are involved in Reaction B but not in Reaction A.
Explanation:
The description of reaction A in which protons are lost or gained by the atom of the element is a nuclear reaction. In nuclear reactions, the nucleons which are the protons and neutrons drives the reaction. No valence electrons in the orbiting shells are involved in this kind of reaction. During this type of reaction, an atom changes it identity to that of another.
Reaction B in which no identity change occurs is a chemical reaction. In chemical reactions bonds are formed by the atoms using the valence electrons that orbits round the central nucleus. The atoms remain the same but it chose to attain stability and an inert configuration by losing or gaining electrons.
The mass percent of hydrogen in CH₄O is 12.5%.
<h3>What is the mass percent?</h3>
Mass percent is the mass of the element divided by the mass of the compound or solute.
- Step 1: Calculate the mass of the compound.
mCH₄O = 1 mC + 4 mH + 1 mO = 1 (12.01 amu) + 4 (1.00 amu) + 1 (16.00 amu) = 32.01 amu
- Step 2: Calculate the mass of hydrogen in the compound.
mH in mCH₄O = 4 mH = 4 (1.00 amu) = 4.00 amu
- Step 3: Calculate the mass percent of hydrogen in the compound.
%H = (mH in mCH₄O / mCH₄O) × 100%
%H = 4.00 amu / 32.01 amu × 100% = 12.5%
The mass percent of hydrogen in CH₄O is 12.5%.
Learn more about mass percent here:brainly.com/question/4336659
Answer is: the maximum concentration of Pb²⁺ is 6.8·10⁻³ M.
Chemical reaction 1: PbCl₂(s) → Pb²⁺(aq) + 2Cl⁻(aq).
Chemical reaction 2: NaCl(aq) → Na⁺(aq) + Cl⁻(aq).
Ksp(PbCl₂) = 1.7·10⁻⁵.
c(NaCl) = c(Cl⁻) = 0.0500 M.
Ksp(PbCl₂) = c(Pb²⁺) · c(Cl⁻)².
c(Pb²⁺) = Ksp(PbCl₂) ÷ c(Cl⁻)².
c(Pb²⁺) = 1.7·10⁻⁵ M³ ÷ (0.0500 M)².
c(Pb²⁺) = 0.000017 M³ ÷ 0.0025 M².
c(Pb²⁺) = 0.0068 M = 6.8·10⁻³ M.
