Answer: This was because the experiment showed that a substance could emit radiation even while it was not exposed to light.
Considering ideal gas behavior, the volume of 1 mol of gas at STP is 22.4 L; then the volume occupied by 1.9 moles is 1.9mol*22.4L/mol = 42. 6 L.
Answer: 43 L
Explanation:
Balanced chemical reaction equation will be as follows.

In human body, the neutral iron changes into
(aq) cation. There will be an oxidation-half reaction and a reduction-half reaction. Equations for this reaction are as follows.
Oxidation: 2Fe^{2+}(aq) \rightleftharpoons 2Fe^{3+}(aq) + 2e^{-}[/tex] .... (1)
Reduction:
...... (2)
On adding both equation (1) and (2), the overall reaction equation will be as follows.

Therefore, neutral iron is a part of Heme - b group of Hemoglobin and in an aqueous solution it dissolutes as a part of Heme group. Hence, then it becomes an
cation.
Answer:
A. fluorine, 1.79 moles
Explanation:
Given parameters:
Mass of carbon = 87.7g
Mass of fluorine gas = 136g
Unknown:
The limiting reactant and the maximum amount of moles of carbon tetrafluoride that can be produced = ?
Solution:
Equation of the reaction:
C + 2F₂ → CF₄
let us find the number of the moles the given species;
Number of moles =
C; molar mass = 12;
Number of moles =
= 7.31moles
F; molar mass = 2(19) = 38g/mol
Number of moles =
= 3.58moles
So;
From the give reaction:
1 mole of C requires 2 moles of F₂
7.31 moles of C will then require 2 x 7.31 moles of F₂ = 14.62moles
But we have 3.58 moles of the F₂;
Therefore, the reactant in short supply is F₂ and it is the limiting reactant;
So;
2 moles of F₂ will produce mole of CF₄
3.58 moles of F₂ will then produce
= 1.79moles of CF₄
The answer is
C. A single replacement reaction (acid reactions)
An example would be the reaction between simple metal Potassium (K) and Water (H2O), resulting in a much solid compound called Potassium Hydroxide (KOH) and hydrogen gas is set free.
K+H2O --> KOH