1. what is the mass number for a neon atom with 15 neutrons? what would the atoms full name be?\n2. what is…

1. what is the mass number for a neon atom with 15 neutrons? what would the atoms full name be?\n2. what is the mass for copper - 75?\n3. how do you calculate average atomic mass?\n4. the element copper has naturally occurring isotopes with mass numbers 63 and 65. the masses are: 62.93 amu (69.2%) and 64.93 (30.8%). calculate the average atomic mass of copper. show all your work. use proper number of sig - figs throughout your work.\n5. rubidium is a soft, silvery - white metal that has two common isotopes, ^85rb and ^87rb. if the abundance of ^85rb is 72.2% and the abundance of ^87rb is 27.8%, what is the average atomic mass of rubidium?\n6. uranium is used in nuclear reactors and is a rare element on earth. uranium has three common isotopes. if the abundance of ^234u is 0.01%, the abundance of ^235u is 0.71%, and the abundance of ^238u is 99.28%, what is the average atomic mass of uranium?\n7. titanium has five common isotopes: ^46ti (8.0%), ^47ti (7.8%), ^48ti (73.4%), ^49ti (5.5%), ^50ti (5.3%). what is the average atomic mass of titanium?\n8. why is the mass in amu of a carbon - 12 atom reported as 12.011 in the periodic table of the elements?\n9. naturally occurring chlorine that is put in pools is 75.53 percent ^35cl (mass = 34.969 amu) and 24.47 percent ^37cl (mass = 36.966 amu). calculate the average atomic mass.\n10. copper used in electric wires comes in two flavors (isotopes): ^63cu and ^65cu
Answer
Explanation:
Step1: Recall mass - number formula
The mass number ($A$) of an atom is the sum of the number of protons and neutrons. Neon has an atomic number ($Z$) of 10 (number of protons). Given 15 neutrons, $A=Z + N$. So $A = 10+15=25$. The full name is neon - 25.
Step2: Copper - 75 mass
Copper - 75 has a mass number of 75. In atomic mass units (amu), the mass is approximately 75 amu.
Step3: Average atomic mass formula
The average atomic mass ($\bar{M}$) of an element with isotopes is calculated as $\bar{M}=\sum_{i = 1}^{n}M_i\times%{i}$, where $M_i$ is the mass of the $i$ - th isotope and $%{i}$ is the percentage abundance of the $i$ - th isotope (expressed as a decimal).
Step4: Calculate copper average atomic mass
For copper: $M_1 = 62.93$ amu, $%_1=0.692$, $M_2 = 64.93$ amu, $%_2 = 0.308$ $\bar{M}=(62.93\times0.692)+(64.93\times0.308)$ $=43.54756+19.99844$ $=63.546\approx63.55$ amu
Step5: Calculate rubidium average atomic mass
For rubidium: $M_1$ (for $^{85}$Rb) $\approx85$ amu, $%_1 = 0.722$, $M_2$ (for $^{87}$Rb) $\approx87$ amu, $%_2=0.278$ $\bar{M}=(85\times0.722)+(87\times0.278)$ $=61.37+24.186$ $=85.556\approx85.56$ amu
Step6: Calculate uranium average atomic mass
For uranium: $M_1$ (for $^{234}$U) $\approx234$ amu, $%_1 = 0.0001$, $M_2$ (for $^{235}$U) $\approx235$ amu, $%_2=0.0071$, $M_3$ (for $^{238}$U) $\approx238$ amu, $%_3 = 0.9928$ $\bar{M}=(234\times0.0001)+(235\times0.0071)+(238\times0.9928)$ $=0.0234 + 1.6685+236.2864$ $=237.9783\approx238.0$ amu
Step7: Calculate titanium average atomic mass
For titanium: $M_1$ (for $^{46}$Ti) $\approx46$ amu, $%_1 = 0.080$, $M_2$ (for $^{47}$Ti) $\approx47$ amu, $%_2=0.078$, $M_3$ (for $^{48}$Ti) $\approx48$ amu, $%_3 = 0.734$, $M_4$ (for $^{49}$Ti) $\approx49$ amu, $%_4=0.055$, $M_5$ (for $^{50}$Ti) $\approx50$ amu, $%_5 = 0.053$ $\bar{M}=(46\times0.080)+(47\times0.078)+(48\times0.734)+(49\times0.055)+(50\times0.053)$ $=3.68+3.666+35.232+2.695+2.65$ $=47.923\approx47.92$ amu
Step8: Carbon - 12 mass in periodic table
The mass of carbon - 12 reported as 12.011 amu in the periodic table is because the periodic - table value is the average atomic mass of carbon, which takes into account the presence of other carbon isotopes (such as carbon - 13) in nature.
Step9: Calculate chlorine average atomic mass
For chlorine: $M_1 = 34.969$ amu, $%_1=0.7553$, $M_2 = 36.966$ amu, $%_2 = 0.2447$ $\bar{M}=(34.969\times0.7553)+(36.966\times0.2447)$ $=26.4321857+9.0456702$ $=35.4778559\approx35.48$ amu
Step10: Copper isotopes in wires
This part seems to be an introduction without a specific question. If the question is about average atomic mass (similar to previous copper cases), we would use the formula $\bar{M}=\sum_{i = 1}^{n}M_i\times%_{i}$ with appropriate abundances of $^{63}$Cu and $^{65}$Cu.
Answer:
- Mass number: 25, Full name: neon - 25
- Approximately 75 amu
- $\bar{M}=\sum_{i = 1}^{n}M_i\times%_{i}$
- 63.55 amu
- 85.56 amu
- 238.0 amu
- 47.92 amu
- Due to presence of other carbon isotopes
- 35.48 amu
- No specific question answered. If about average atomic mass, use $\bar{M}=\sum_{i = 1}^{n}M_i\times%_{i}$