"Aristotle," thought that everything was made from "earth", "air", "fire" and "water".
Option: D
Explanation:
"Aristotle" was against to "Atomic theory" so he believed that all the things were made from earth, air, fire and water called "four classical elements". These are "four classical elements" responsible for creating all the things in "terrestrial spheres". "Aristotle" started believing that all many of the little substances were "made up" of these "four classical elements" earth, air, fire and water. But "Aristotle" views on "elements" went wrong. "Aristotle" also grasped that "heavens" are created by using "weightless" and "unchangeable" the "fifth element" called "Aether".
Answer:
a simple covalent structure
Explanation:
its has a few non-metal atoms?
Answer:
b) beta decay
Explanation:
Beta radiations:
Beta radiations are result from the beta decay in which electron is ejected. The neutron inside of the nucleus converted into the proton an thus emit the electron which is called β particle.
The mass of beta particle is smaller than the alpha particles.
They can travel in air in few meter distance.
These radiations can penetrate into the human skin.
The sheet of aluminium is used to block the beta radiation
⁴₆C → ¹⁴₇N + ⁰₋₁e
The beta radiations are emitted in this reaction. The one electron is ejected and neutron is converted into proton.
The answer is: "Twelve (12) moles of Fe (iron) would be required."
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or:
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The answer is: "12" .
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Note: The balanced chemical equation is given:
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4 Fe + 3 O₂ → 2 Fe₂O₃
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The product is: 2 moles of Fe₂O₃ ; that is, "2 moles of iron (III) oxide" .
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→ If SIX (6) moles of iron oxide were produced, that would be "3 (three) times the number of moles of iron oxide produced (3 TIMES 2) ;
→ since: "6 ÷ 2 = 3" ; and since the equation is balanced.
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→ So we want to find the number of moles of "iron (Fe)" needed in such a situation. In the balanced chemical, we have "4 Fe" (that is, "FOUR (4) moles of iron") ; so we multiply that number by "3", proportionally:
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→ 4 (moles Fe) * (3) = 12 (moles Fe) .
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Answer:
14.5 g silver
Explanation:
This is a problem using the stoichiometry of the reaction. First thing we need is the balanced equation:
Zn + 2 AgNO3 ----------------------- 2 Ag + Zn(NO3)2
We know that 14.6 g of Zn did not reacted, then we can calculate the amount of Zn reacted and do the calculation given the above reaction.
amount Zn reacted: 19.0 -14.6 g Zn = 4.4 g Zn
atomic weight of Zn: 65.37 g/mol
mol Zn reacted: 4.4 g Zn x ( 1 mol Zn/ 65.37 g Zn) = 0.067 mol Zn
We know from the balanced equation that moles of Ag are produced from 1 mol Zn therefore the mol of Ag produced are:
0.067 mol Zn x 2 mol Ag/ 1mol Zn = 0.135 mol Ag
and the mass of silver then will be given by multiplying by the atomic weight of silver:
0.135 mol Ag x 107.9 g/mol = 14.5 g Ag