If an element has 9 protons and 10 neutrons and 9 electrons,which expression correctly identifies the element?
A) $\begin{array} { c }
19 \
9
\end{array}$ F
B) $\begin{array} { c }
9 \
19
\end{array}$ F
C) $\begin{array} { c }
19 \
9
\end{array}$ K
D) $\begin{array} { c }
9 \
19
\end{array}$ K
E) $\begin{array} { c }
19 \
19
\end{array}$

Question

If an element has 9 protons and 10 neutrons and 9 electrons,which expression correctly identifies the element?
A) $\begin{array} { c } 
19 \
9
\end{array}$ F
B) $\begin{array} { c } 
9 \
19
\end{array}$ F
C) $\begin{array} { c } 
19 \
9
\end{array}$ K
D) $\begin{array} { c } 
9 \
19
\end{array}$ K
E) $\begin{array} { c } 
19 \
19
\end{array}$

Quizplus · Accepted Answer

The correct notation for an element in the periodic table includes the atomic number (number of protons) as the subscript and the mass number (sum of protons and neutrons) as the superscript. For an element with 9 protons, 10 neutrons, and 9 electrons, the atomic number is 9 (which corresponds to Fluorine, F), and the mass number is 19 (9 protons + 10 neutrons). Therefore, the correct expression is $\begin{array}{c} 19 \ 9 \end{array}$ F.

If an Element Has 9 Protons and 10 Neutrons and 9