Answer:
The isotope with the greatest number of protons is:
- <u>option D: Pu-239, with 94 protons</u>
Explanation:
The number of <em>protons</em> is the atomic number and is a unique number for each type of element.
You can tell the number of protons searching the element in a periodic table and reading its atomic number.
Thus, this is how you tell the number of protons or each isotope
Sample Chemical symbol Element atomic number # of protons
A Pa-238 Pa protactinium 91 91
B U-240 U uranium 92 92
C Np-238 Np neptunium 93 93
D Pu-239 Pu plutonium 94 94
6 Na + 1 Fe₂O₃ → 3 Na₂O + 6 Fe
<h3>Explanation</h3>
Method One: Refer to electron transfers.
Oxidation states:
- Na: from 0 to +1; loses one electron.
- Fe: from +3 to 0; gains three electrons.
Each mole of Fe₂O₃ contains two Fe atoms and will gain 2 × 3 = 6 electrons during the reaction. It takes 6 moles of Na to supply all those electrons.
6 Na + 1 Fe₂O₃ → ? Na₂O + ? Fe
- There are two moles of Na atoms in each mole of Na₂O. 6 moles of Na will make 3 moles of Na₂O.
- There are two moles of Fe atoms in each mole of Fe₂O₃. 1 mole of Fe₂O₃ will make 2 moles of Fe.
6 Na + 1 Fe₂O₃ → 3 Na₂O + 2 Fe
Method Two: Atoms conserve.
Fe₂O₃ has the largest number of atoms among one mole of all four species in this reaction. Assume <em>one</em> as its coefficient.
? Na + <em>1</em> Fe₂O₃ → ? Na₂O + ? Fe
There are two moles of Fe atoms and three moles of O atoms in each mol of Fe₂O₃. One mole of Fe₂O₃ contains two moles of Fe and three moles of O. There are one mole of O atom in every mole of Na₂O. Three moles of O will go to three moles of Na₂O.
? Na + <em>1</em> Fe₂O₃ → <em>3</em> Na₂O + <em>2</em> Fe
Each mole of Na₂O contains two moles of Na. Three moles of Na₂O will contain six moles of Na.
<em>6</em> Na + <em>1</em> Fe₂O₃ → <em>3</em> Na₂O + <em>2</em> Fe
Simplify the coefficients. All coefficients in this equation are now full number and relatively prime. Hence the equation is balanced.
6 Na + 1 Fe₂O₃ → 3 Na₂O + 2 Fe
It actually depends on the percentage of the concentration give. Percentages can be expressed as %mass/mass, %volume/volume or %mass/volume. To keep things simple, let's just assume that it is in %volume/volume. Thus, 13% of 520 mL is pure acid.
Volume of pure acid = 520*0.13 = 67.6 mL
Answer:
hello hope this helps :)
a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.
Explanation:
Chemical change occur when two substances are combined and produces a new substance or decomposes into two or more substances which are entirely different from the original two substances.
There are three types of chemical changes. These are 1) Inorganic Changes, 2) Organic Changes, and 3) Biochemical Changes
Here are some examples of chemicsal changes.
If you combine Sodium and Water, chemical changes causes decomposition into Sodium Hydroxide and Hydrogen.
Sodium + Water ==> Sodium Hydroxide and Hydrogen
Na + H2O ====> NaOH and H
Another example of chemical change is:
Carbon Dioxide and Water will decompose into Sugar and Oxygen
Carbon Dioxide + Water ==> Sugar and Oxygen
CO2 + H2O ==> CnH2nOn (where n is between 3 and 7) and O
