Answer:
1.31moles
Explanation:
Given parameters:
Mass of CuO₂ = 125g
Unknown:
Number of moles = ?
Solution:
To solve this problem, we use the expression below:
Number of moles =
Molar mass of CuO₂ = 63.6 + 2(16) = 95.6g/mol
So;
Number of moles = = 1.31moles
The valence electrons of metals jump easily to a higher energy orbital when light shines on them then they all fall emitting the excess energy as light show lustrous property of metals.
Valence electrons are defined as a negatively charged particle that can be shared or transmitted between atoms that is found in the outermost shell of an atom. Valence electrons have a crucial role in determining how an atom will behave. The electrical configurations of elements can be used to find valence electrons. The total number of valence electrons in that element is then determined by counting the number of electrons in the outermost shell.
When newly treated, polished, or broken, a material takes on a bright look and conducts electricity and heat reasonably well. Metals are typically ductile and malleable. These traits are the result of the metallic bond that connects the atoms or molecules of the metal.
Thus, the valence electrons of metals jump easily to a higher energy orbital when light shines on them then they all fall emitting the excess energy as light show lustrous property of metals.
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Answer:
Lustrous
Explanation:
Metals are lustrous which gives them a property of having Shiny surfaces
To dissolve a 3.94g copper penny, we would need approximately 331 milliliters of 1.50 M HNO3, taking into consideration the stoichiometry of the copper-nitric acid reaction.
Stoichiometry is required to solve this chemistry problem. The balanced equation for the reaction between copper and nitric acid is: 3Cu(s) + 8HNO3(aq) → 2NO(g) + 3Cu(NO3)2(aq) + 4H2O(l)
From this, we can conclude that every mole of copper reacts with eight moles of nitric acid. The molecular weight of copper is approximately 63.546 g/mole, so the moles of copper in an old penny can be calculated by mass (3.94 g) divided by the molar mass (63.546 g/mol).
This calculation shows that there are approximately 0.062 moles of copper in a penny. Since we determined that eight moles of nitric acid are required to react with one mole of copper, eight times the moles of copper gives the moles of nitric acid required, which is 0.496 moles.
Since molarity (M) = moles/liters, we can find out the volume of 1.50 M HNO3 required by rearranging the formula to be Liters= moles/Molarity. So, 0.496 moles divided by 1.50 M gives roughly 0.331 liters, which can be converted to approximately 331 milliliters.
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To solve this we must be knowing each and every concept related to element. Therefore, "all of the noble gas elements except neon have 8 electrons in their outermost energy level" is a false element.
A chemical element represents a material that cannot be degraded chemically. Although chemical processes do not modify atoms, nuclear reactions can produce new elements.
Elements are classified according to the amount of protons they have. An element's atoms typically have the same amount of protons, but differing amounts of electrons or neutrons.
There are 118 recognized elements. Element 120.1 is being researched. When element 120 is created and validated, the periodic table must be updated to include it. A numerical subscript following an element in a chemical formula mean number of atoms. All of the noble gas elements except have 8 electrons in their outermost energy level.
Therefore, "all of the noble gas elements except neon have 8 electrons in their outermost energy level" is a false element.
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