Identify the group and valency of the element having atomic number 119. Also predict the outermost electronic

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Q. Identify the group and valency of the element having atomic number 119. Also predict the outermost electronic configuration and write the general formula of its oxide.

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Concept understanding — Element Nomenclature

Element Nomenclature: What Do We Call an Element?

Imagine you discover a new island. You can't just call it "that place" — you need a name, a symbol on a map, and a way to write it in official documents. The same happens when scientists discover a new element. Element nomenclature is the system of naming, symbolising, and writing the names of chemical elements.

The Intuition: Why Bother with Rules?

Before the modern system, elements had chaotic names. Hydrogen was called "inflammable air," oxygen was "dephlogisticated air." Imagine memorising 118 such names. Worse, different countries used different names for the same element — iron was ferrum in Latin, loh in Hindi, Eisen in German. Scientists couldn't communicate clearly.

So the International Union of Pure and Applied Chemistry (IUPAC) stepped in. They created a universal system so that a chemist in Tokyo, a student in Mumbai, and a researcher in Paris all mean the same thing when they write "Fe" or "sodium."

The Precise Statement

Element nomenclature has three layers:

The name — a unique, official English name (e.g., sodium, gold, carbon)
The symbol — a one- or two-letter abbreviation (e.g., Na, Au, C)
The systematic name — a temporary, descriptive name for newly discovered elements before they get a permanent name

Permanent name : chosen by discoverers, approved by IUPAC Symbol : first letter capital, second letter lowercase (never "NA" or "na") Systematic name : based on atomic number (e.g., element 118 = ununoctium, symbol Uuo)

The Rules in Detail

1. Permanent Names and Symbols

First letter always capital, second letter always lowercase: Co (cobalt), not CO; Na (sodium), not NA.
Symbols often come from Latin names: Ferrum → Fe (iron), Aurum → Au (gold), Stannum → Sn (tin).
Some symbols come from German: Wolfram → W (tungsten).
Newer elements are named after people, places, or properties: Curium (Cm) after Marie Curie, Californium (Cf) after California, Technetium (Tc) from Greek technetos (artificial).

Watch out

Never write "CO" for cobalt — that's carbon monoxide. Never write "NA" for sodium — that's not a valid symbol. The case matters.

2. Systematic Names for New Elements

When a new element is discovered (say, element 117), it gets a temporary name until IUPAC approves a permanent one. The systematic name is built from the atomic number using these roots:

Digit	Root
0	nil
1	un
2	bi
3	tri
4	quad
5	pent
6	hex
7	sept
8	oct
9	enn

The name is formed by stringing the roots together, then adding -ium. For element 117: 1-1-7 = un-un-sept-ium = ununseptium (symbol Uus). When it got its permanent name, it became tennessine (Ts).

Tip

|:---:|:---:|:---:|:---:|

| 113 | ununtrium | Uut | nihonium (Nh) |

| 115 | ununpentium | Uup | moscovium (Mc) |

| 117 | ununseptium | Uus | tennessine (Ts) |

| 118 | ununoctium | Uuo | oganesson (Og) |

3. Spelling and Pronunciation

Names are not capitalised in English (except at the start of a sentence): "sodium chloride," not "Sodium chloride."
British vs. American spelling: aluminium (UK) vs. aluminum (US) — both accepted, but IUPAC uses aluminium. …

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The element with atomic number 119 belongs to Group 1 (alkali metals), has a valency of 1, its outermost electronic configuration is $8s^1$ , and its oxide has the general formula $M_2O$ .

Why This Approach Works

The periodic table is built on the principle that elements with the same number of valence electrons fall into the same group. For an element as heavy as atomic number 119, we cannot rely on memory — we must reconstruct its position by understanding how electron shells fill. The key is to know the order of orbital filling (Aufbau principle) and the block structure of the periodic table: s-block (Groups 1–2), p-block (Groups 13–18), d-block (Groups 3–12), and f-block (lanthanides/actinides). Once we know which block and which group the element lands in, its valency and oxide formula follow directly from its valence electron count.

Step-by-Step Solution

1. Determine the electron configuration up to the previous noble gas.

The last noble gas before element 119 is oganesson (atomic number 118). Its configuration is:

$1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^2 4d^{10} 5p^6 6s^2 4f^{14} 5d^{10} 6p^6 7s^2 5f^{14} 6d^{10} 7p^6$

This fills up to the $7p$ subshell. The next electron (the 119th) must go into the $8s$ orbital, because after $7p$ , the next available orbital in the Aufbau order is $8s$ .

2. Write the full configuration for element 119.

Element 119 = [Og] $8s^1$

The outermost shell is the 8th shell, and it contains exactly one electron in the $s$ orbital.

3. Identify the group.

The $8s^1$ configuration places this element in the s-block. All s-block elements with one $s$ electron belong to Group 1 (the alkali metals). This is true regardless of the principal quantum number — lithium ( $2s^1$ ), sodium ( $3s^1$ ), potassium ( $4s^1$ ), rubidium ( $5s^1$ ), caesium ( $6s^1$ ), and francium ( $7s^1$ ) are all Group 1. Element 119 simply continues the pattern.

Watch out

A common mistake is to think that because the element is so heavy, it might belong to a different block or group. But the periodic table's group numbering is based on valence electrons, not on atomic mass. The $8s^1$ configuration is unambiguous — it is Group 1.

4. Determine the valency. …

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Q.Identify the group and valency of the element having atomic number 119. Also predict the outermost electronic configuration and write the general formula of its oxide.

Why This Approach Works

Step-by-Step Solution

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