Question

The atomic number of the element with systematic name of Ununnilium is

• A. \(101\)
• B. \(109\)
• C. \(110\)
• D. \(111\)

Hint:

Remember the commonly used numerical roots: \[ \begin{aligned} 1 &\rightarrow \text{un} \\ 2 &\rightarrow \text{bi} \\ 3 &\rightarrow \text{tri} \\ 0 &\rightarrow \text{nil} \end{aligned} \] Ununnilium \(=\) Un + Un + Nil \(=\) \(110\).

Answer 1

The Correct Option is C

Step 1: Understand the naming trick.
For very heavy elements, IUPAC builds a temporary name straight from the digits of the atomic number using fixed roots.

Step 2: List the digit roots.
The roots are: nil $=0$, un $=1$, bi $=2$, tri $=3$, quad $=4$, pent $=5$, hex $=6$, sept $=7$, oct $=8$, enn $=9$.

Step 3: Break the given name.
Ununnilium splits as un-un-nil-ium.

Step 4: Replace each root with its digit.
un $\to 1$, un $\to 1$, nil $\to 0$. So the digits read $1, 1, 0$.

Step 5: Read the number.
Put together the digits give $110$.

Step 6: State the answer.
So Ununnilium stands for atomic number $110$ (now called Darmstadtium).
\[ \boxed{110} \]