<span>Permeable means that a material is full of tiny, connected airspaces that allows water to seep through it.</span>
Hydrogen gas is produced when dilute hydrochloric acid is added to a reactive metal.
Balanced molecular equation of sodim metal with hydrochloric acid:
2Na(s) + 2HCl(aq) → 2NaCl(aq) + H₂(g).
Ionic equation: 2Na(s) + 2H⁺(aq) + 2Cl⁻(aq) → 2Na⁺ + 2Cl⁻(aq) + H₂(g).
Net ionic equation: 2Na(s) + 2H⁺(aq) → 2Na⁺(aq) + H₂(g).
Sodium is oxidized from oxidation number 0 (Na) to oxidation number +1, hydrogen is reduced from oxidation number +1 to oxidation number 0 (hydrogen gas H₂).
Another example:
Balanced chemical equation: Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)
Word equation: zinc + hydrochloric acid → zinc chloride + hydrogen gas
More about hydrogen gas:brainly.com/question/24433860
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"John Dalton" is the one scientist among the following choices given in the question that <span>came up with the first widely recognized atomic theory. The correct option among all the options that are given in the question is the first option or option "A". I hope that this is the answer that has come to your help.</span>
The average atomic mass of an element can be determined by multiplying the individual masses of the isotopes with their respective relative abundances, and adding them.
Average atomic mass of Br = 158 amu(0.2569) + 160 amu(0.4999) + 162 amu(0.2431)
Average atomic mass = 159.96 amu
As described in the problem, the relative abundance for Br-79 is 25.69%. This is because 2 atoms of Br is equal to 79*2 = 158 amu. Similarly, the relative abundance of Br-81 is 81*2 = 162, which is 24.31%.