module 4: electrons in atoms test - 11/14/2025
the electron configuration below represents a ground - state atom of which element?
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p³
thallium
bismuth
lead
polonium

Question

Accepted Answer

# Explanation:
## Step1: Calculate the total number of electrons
The sum of the exponents in the electron configuration gives the number of electrons.
$$
\begin{align*}
&2 + 2+6 + 2+6+2 + 10+6+2+10+6+2+14+10+3\
=&(2 + 2)+(6 + 2)+6+(2 + 10)+6+(2 + 10)+6+(2 + 14)+10+3\
=&4+8 + 6+12+6+12+6+16+10+3\
=&(4 + 8)+(6 + 12)+(6 + 12)+(6 + 16)+(10 + 3)\
=&12+18+18+22+13\
=&(12 + 18)+(18 + 22)+13\
=&30+40+13\
=&83
\end{align*}
$$
## Step2: Relate the number of electrons to atomic number
In a ground - state atom, the number of electrons is equal to the atomic number. The atomic number $Z = 83$.

## Step3: Identify the element
Looking at the periodic table, the element with atomic number $Z = 83$ is Bismuth ($Bi$).

# Answer:
Bismuth

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QUESTION IMAGE

Question

Explanation:

Step1: Calculate the total number of electrons

Step2: Relate the number of electrons to atomic number

Step3: Identify the element

Answer: