Chapter 2 · Section 3Textbook pages 25–29

The Modern Periodic Table: Periods, Groups and Families പീരിയഡുകൾ, ഗ്രൂപ്പുകൾ, മൂലക കുടുംബങ്ങൾ

Here is the whole modern periodic table of textbook Fig 2.1 – all 118 elements – as a table you can tap. Use it to answer the textbook's questions: how many periods and groups are there, which period is shortest, what does one cell tell you? Then complete Table 2.1, discover what all the elements of one group have in common, and meet the nine element families of Table 2.2.

📖 What you need (pages 2 and 4 of this guide)

Electron configuration ഇലക്ട്രോൺ വിന്യാസം lists the electrons shell by shell: sodium 2, 8, 1. The last number is the number of outermost electrons ബാഹ്യതമ ഇലക്ട്രോണുകൾ (page 2).
The modern table is arranged in increasing atomic number. Horizontal rows are periods, vertical columns are groups (page 4).

1. The modern periodic table (Fig 2.1)

Each cell shows the atomic number, the symbol, the name and the electron configuration, exactly as in the textbook. Periods are numbered I–VII down the left, groups 1–18 across the top. Tap any element to open its card below the table. On a phone, swipe the table sideways.

🧪 Interactive periodic table (textbook Fig 2.1)

colours light up period group

show configurations

The colours of the book key are those of textbook Fig 2.1 (gallium, caesium and francium are coloured as liquids there: they melt just above room temperature – go further). Electron configurations of the heavier elements follow rules you will learn in higher classes; this guide copies them from Fig 2.1. The textbook asks you to check things with the Kalzium software – this table does the same job, offline.

2. How to read one cell

The key box in Fig 2.1 സൂചനകൾ shows the order of the information in every cell: അറ്റോമിക നമ്പർ · പ്രതീകം · പേര് · ഇലക്ട്രോൺ വിന്യാസം – atomic number, symbol, name, electron configuration.

🔎 One cell, four facts

Q (page 28). ഒരു മൂലകത്തെ സംബന്ധിച്ച് എന്തെല്ലാം വിവരങ്ങളാണ് പീരിയോഡിക് ടേബിളിൽ നിന്നും ലഭിക്കുന്നത്? സയൻസ് ഡയറിയിൽ രേഖപ്പെടുത്തുക. What information about an element do you get from the periodic table? Record it in your science diary. (The book starts the list: • name പേര് • symbol പ്രതീകം • … )

name (and the Latin name where the symbol comes from it, e.g. Natrium → Na) and symbol;
atomic number – so also the number of protons and electrons;
electron configuration – so the number of shells and of outermost electrons;
the period (row) and the group (column) it belongs to – and so its family;
its physical state at room temperature (gas / liquid / solid – from the colour key) and whether it is an artificial element.

3. Newly discovered elements (2016)

📦 Box – പുതിയതായി കണ്ടെത്തിയ മൂലകങ്ങൾ (newly discovered elements, page 27)

In 2016 four more elements were added to the periodic table. They are placed in the 7th period.

Atomic number അറ്റോമിക നമ്പർ	Symbol പ്രതീകം	IUPAC name
113	Nh	നിഹോണിയം Nihonium
115	Mc	മോസ്കോവിയം Moscovium
117	Ts	ടെന്നെസിൻ Tennessine
118	Og	ഒഗനെസൻ Oganesson

Nihonium – from the Japanese word Nihon, meaning Japan; it also means "the land of the rising sun".
Moscovium – the experiments connected with its discovery were done mainly in laboratories in Moscow.
Tennessine – from experiments in laboratories in the Tennessee region (USA). These three names come from the places linked with their discovery.
Oganesson – named to honour the nuclear scientist Prof. Yuri Oganessian. It is only the second element named after a living scientist; the first was seaborgium (atomic number 106), named in honour of the American chemist Glenn Seaborg.

മൂലകങ്ങളുടെ ഇലക്ട്രോൺ വിന്യാസവും പീരിയോഡിക് ടേബിളിലെ സ്ഥാനവും – Now let us study the link between the electron configuration of an element and its place in the periodic table.

4. Counting periods, groups and elements (pages 27–28)

ആധുനിക പീരിയോഡിക് ടേബിൾ (ചിത്രം 2.1) വിശകലനം ചെയ്ത് ചുവടെ കൊടുത്തിരിക്കുന്ന ചോദ്യങ്ങൾക്ക് ഉത്തരം കണ്ടെത്താമല്ലോ. – Analyse the modern periodic table (Fig 2.1) and find the answers. Use the counter first, then check each answer.

🔢 Elements in each period

Q1. പീരിയഡുകളുടെ എണ്ണമെത്ര? How many periods are there?

7 periods (I to VII). The lanthanoid and actinoid rows below the table are not extra periods – they belong to periods 6 and 7.

Q2. ഗ്രൂപ്പുകളുടെ എണ്ണം എഴുതുക. Write the number of groups.

18 groups (1 to 18).

Q3. മൂലകങ്ങളുടെ എണ്ണം ഏറ്റവും കുറവുള്ള പീരിയഡ് ഏത്? Which period has the fewest elements?

Period 1 – only 2 elements, hydrogen (H) and helium (He). Their atoms have just one shell (K), which holds at most 2 electrons.

Q4. 2-ഉം 3-ഉം പീരിയഡുകളിലെ മൂലകങ്ങളുടെ എണ്ണം ഒരുപോലെയാണോ? Do periods 2 and 3 have the same number of elements?

Yes – 8 each: period 2 from lithium (3) to neon (10), period 3 from sodium (11) to argon (18).

Q5. 4-ാം പീരിയഡിൽ എത്ര മൂലകങ്ങളാണ് ഉൾപ്പെടുത്തിയിരിക്കുന്നത്? How many elements are there in the 4th period?

18 elements – from potassium (19) to krypton (36), including the ten transition elements scandium (21) to zinc (30).

5. Group 1 and group 2: outermost electrons (Table 2.1)

🧑‍💻 Side note (page 28)
പട്ടിക 2.1 പൂർത്തിയാക്കി Kalzium സോഫ്റ്റ്‌വെയർ ഉപയോഗിച്ച് ശരിയാണെന്ന് ഉറപ്പാക്കുക. Complete Table 2.1 and check it with the Kalzium software – or with the interactive table above (set "light up group" to 1).

ഒന്നാം ഗ്രൂപ്പ് മൂലകങ്ങളാണ് പട്ടികയിൽ നൽകിയിരിക്കുന്നത്. പട്ടിക 2.1 പൂർത്തിയാക്കുക. – The elements of group 1 are given in the table. Complete Table 2.1. Type into the empty boxes (configurations like 2,8,1), then press Check.

✍ Table 2.1 – group 1 elements

Q (page 28). ഒന്നാം ഗ്രൂപ്പ് മൂലകങ്ങളിൽ ബാഹ്യതമ ഇലക്ട്രോണുകളുടെ എണ്ണത്തിൽ എന്തെങ്കിലും പ്രത്യേകതയുണ്ടോ? Is there anything special about the number of outermost electrons of the group 1 elements?

Yes – every group 1 element has 1 electron in its outermost shell (Li 2,1 · Na 2,8,1 · K 2,8,8,1 · Rb 2,8,18,8,1 · Cs 2,8,18,18,8,1 · Fr 2,8,18,32,18,8,1). Hydrogen (1) at the top of group 1 also has 1 electron.

Q (page 28). രണ്ടാം ഗ്രൂപ്പ് മൂലകങ്ങളുടെ ഇലക്ട്രോൺ വിന്യാസം പീരിയോഡിക് ടേബിളിന്റെ സഹായത്തോടെ എഴുതൂ. Write the electron configurations of the group 2 elements with the help of the periodic table.

✍ Group 2 elements – configurations and outermost electrons

⭐ What you have found (page 28)

ഒരേ ഗ്രൂപ്പിൽ ഉൾപ്പെട്ട മൂലകങ്ങളുടെ ബാഹ്യതമ ഇലക്ട്രോണുകളുടെ എണ്ണം ഒരുപോലെയാണ്.

Elements of the same group have the same number of outermost electrons – 1 in group 1, 2 in group 2.

മൂലകങ്ങളുടെ രാസഗുണങ്ങൾക്കടിസ്ഥാനം അവയുടെ ബാഹ്യതമ ഷെല്ലിലെ ഇലക്ട്രോണുകളുടെ എണ്ണമാണ്. സാധാരണയായി ഈ ഇലക്ട്രോണുകളാണ് രാസപ്രവർത്തനങ്ങളിൽ പങ്കെടുക്കുന്നത്.

The chemical properties of elements depend on the number of electrons in their outermost shell; usually it is these electrons that take part in chemical reactions രാസപ്രവർത്തനങ്ങൾ. That is why the elements of a group behave alike.

🔭 Group explorer – same outermost electrons, down the group

Inner shells are drawn as thin rings (their electron numbers are in the configuration below); only the outermost electrons are drawn as dots. The rings are drawn to one scale, so you can also see the atoms getting bigger down a group – more about that on page 9.

6. Families of elements (Table 2.2)

ഓരോ ഗ്രൂപ്പിലെയും മൂലകങ്ങളുടെ പൊതുവായ സവിശേഷതകളുടെ അടിസ്ഥാനത്തിൽ അവയെ മൂലക കുടുംബങ്ങളായി പരിഗണിക്കാം. – On the basis of their common features, the elements of each group can be treated as a family of elements മൂലക കുടുംബങ്ങൾ. Look at the list of families in Table 2.2. Press Show to light the family up in the big table.

Table 2.2 (textbook page 29) – members listed from this guide's element data
Group number ഗ്രൂപ്പ് നമ്പർ	Name of the family മൂലക കുടുംബത്തിന്റെ പേര്	Members

Hydrogen sits at the top of group 1 because it has 1 outermost electron, but it is a gas and a non-metal – it is not counted as an alkali metal. The families of groups 13–16 are named after their first element.

🌴 Families you have met

Alkali metals: the sodium in common salt and in the yellow street lamps. Alkaline earth metals: calcium in your bones, in chalk and in the lime (ചുണ്ണാമ്പ്) used with betel leaves. Halogens: the chlorine that disinfects water tanks, the fluoride in toothpaste, the iodine in iodised salt. Noble gases: the neon of shop signboards and the helium of festival balloons. Transition elements: the iron, copper and gold of everyday Kerala life (page 7).

🌐 Explore online needs internet · opens in a new tab

🧪 Periodic Table (interactive) Ptable
Click any element; switch to the 'Electrons' and 'Properties' views to see trends.
📄 Periodic Table of Elements Los Alamos National Laboratory
A page for every element with its history, sources and uses.
📄 Periodic Table of the Elements NIST
Printable periodic tables from the US standards laboratory.
📄 Periodic Table of Elements (official) IUPAC
The latest official table from the organisation that names the elements.
🧪 Kalzium KDE Applications
The free periodic-table program the textbook asks you to use.
📄 Lanthanide Wikipedia
The 15 elements from lanthanum to lutetium (the rare earths).
📄 IUPAC announces the names of elements 113, 115, 117 and 118 IUPAC
The 2016 announcement of nihonium, moscovium, tennessine and oganesson.
📄 Glenn T. Seaborg – Facts NobelPrize.org
The chemist after whom element 106 is named.

7. Check yourself

🧭 Summary

The modern periodic table has 118 elements, 7 periods and 18 groups. Elements per period: 2, 8, 8, 18, 18, 32, 32. The lanthanoids and actinoids are written in two rows below the table but belong to periods 6 and 7.
Each cell gives the atomic number, symbol, name and electron configuration; the colour key shows gases, liquids and artificial elements.
In 2016 four elements were added to period 7: nihonium (113), moscovium (115), tennessine (117) and oganesson (118).
Elements of a group have the same number of outermost electrons (group 1: 1; group 2: 2). Outermost electrons decide chemical properties, so a group's elements behave alike – they form a family.
Families (Table 2.2): 1 alkali metals · 2 alkaline earth metals · 3–12 transition elements · 13 boron family · 14 carbon family · 15 nitrogen family · 16 oxygen family · 17 halogens · 18 noble gases.

Next: Main group elements – finding the group and period number ▶