Answer:
Explanation:
The average atomic mass is the sum of the product of the given masses and their abundances. We have to complete two steps for each isotope, then add all the products together.
<u>Fe-54</u>
Convert the percent abundance to a decimal by dividing by 100.
Multiply the abundance as a decimal by the mass number. This is the number after the element in the isotope symbol (54 amu).
<u>Fe-56</u>
Convert the percent to a decimal.
Multiply the decimal by the mass number (56 amu).
- 0.91754 * 56= 51.38224 amu
<u>Fe-58</u>
Convert the percent to a decimal.
Multiply by the mass number (58 amu).
- 0.02119 * 58 = 1.22902 amu
<u>Average Atomic Mass</u>
Add all the products together to find the average atomic mass.
- 3.1563 amu + 51.38224 amu + 1.22902 amu =55.76756 amu
The average atomic mass given the percent abundance is <u>55.7656 atomic mass units.</u>
Answer:
Each oxygen atom is connected to the central O atom with 2 covalent bonds.
Explanation:
Oxygen atoms are connected by two covalent bonds in the oxygen molecule from the Lewis structure, we see that the bond order for O2 is 2 (a double bond) this is clearly seen in the image attached. There are no resonance structures for the oxygen molecule since there are no partial bonds in the molecule, only the two covalent bonds present.
This structure of oxygen shown in the image is its only structure, showing the covalent bonds formed and other non bonding electrons present in the molecule. The octet rule is followed in drawing the structure. Each oxygen atom possesses an octet of electrons on its outermost shell.
Another explanation
A Lewis structure is also called a dot electron structure. A Lewis structure represents all the valence electrons on atoms in a molecule as dots. Lewis structures can be used to represent molecules in which the central atom obeys the octet rule as well as molecules whose central atom does not obey the octet rule.
Sometimes, one Lewis structure does not suffice in explaining the observed properties of a given chemical specie. In this case, we evoke the idea that the actual structure of the chemical specie lies somewhere between a limited number of bonding extremes called resonance or canonical structures.
The canonical structure of the carbonate ion as well as the lewis structure of phosphine is shown in the image attached to this answer.
Explanation:
<h3>Answer:</h3>
Rubidium (Rb)
<h3>Explanation:</h3>
Ionization Energy is defined as, "the minimum energy required to knock out or remove the valence electron from valence shell of an atom".
<h3>Trends in Periodic table:</h3>
Along Periods:
Ionization Energy increases from left to right along the periods because moving from left to right in the same period the number of protons (atomic number) increases but the number of shells remain constant hence, resulting in strong nuclear interactions and electrons are more attracted to nucleus hence, requires more energy to knock them out.
Along Groups:
Ionization energy decreases from top to bottom along the groups because the number of shells increases and the distance between nucleus and valence electrons also increases along with increase in shielding effect provided by core electrons. Therefore, the valence electrons experience less nuclear attraction and are easily removed.
<h3>Conclusion:</h3>
Given elements belong to same group hence, Rubidium present at the bottom of remaining elements will have least ionization energy due to facts explained in trends of groups above.
