Periodic table (big) Facts for Kids

The periodic table is like a giant map of all the known chemical elements in the universe! It helps scientists and students understand how different elements are related to each other and how they behave. Each element is a basic substance that cannot be broken down into simpler ones. Think of them as the building blocks of everything around us, from the air we breathe to the stars in the sky.

This amazing chart organizes elements based on their atomic number (which is the number of protons in an atom's nucleus). It also groups them by their chemical properties, meaning how they react with other elements.

Group	1	2		3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
	I	II												III	IV	V	VI	VII	VIII
Period
1	hydrogen 1 H																		helium 2 He
2	lithium 3 Li	beryllium 4 Be												boron 5 B	carbon 6 C	nitrogen 7 N	oxygen 8 O	fluorine 9 F	neon 10 Ne
3	sodium 11 Na	magnesium 12 Mg												aluminium 13 Al	silicon 14 Si	phosphorus 15 P	sulfur 16 S	chlorine 17 Cl	argon 18 Ar
4	potassium 19 K	calcium 20 Ca		scandium 21 Sc	titanium 22 Ti	vanadium 23 V	chromium 24 Cr	manganese 25 Mn	iron 26 Fe	cobalt 27 Co	nickel 28 Ni	copper 29 Cu	zinc 30 Zn	gallium 31 Ga	germanium 32 Ge	arsenic 33 As	selenium 34 Se	bromine 35 Br	krypton 36 Kr
5	rubidium 37 Rb	strontium 38 Sr		yttrium 39 Y	zirconium 40 Zr	niobium 41 Nb	molybdenum 42 Mo	technetium 43 Tc	ruthenium 44 Ru	rhodium 45 Rh	palladium 46 Pd	silver 47 Ag	cadmium 48 Cd	indium 49 In	tin 50 Sn	antimony 51 Sb	tellurium 52 Te	iodine 53 I	xenon 54 Xe
6	caesium 55 Cs	barium 56 Ba	*	lutetium 71 Lu	hafnium 72 Hf	tantalum 73 Ta	tungsten 74 W	rhenium 75 Re	osmium 76 Os	iridium 77 Ir	platinum 78 Pt	gold 79 Au	mercury 80 Hg	thallium 81 Tl	lead 82 Pb	bismuth 83 Bi	polonium 84 Po	astatine 85 At	radon 86 Rn
7	francium 87 Fr	radium 88 Ra	**	lawrencium 103 Lr	rutherfordium 104 Rf	dubnium 105 Db	seaborgium 106 Sg	bohrium 107 Bh	hassium 108 Hs	meitnerium 109 Mt	darmstadtium 110 Ds	roentgenium 111 Rg	copernicium 112 Cn	ununtrium 113 Uut	ununquadium 114 Uuq	ununpentium 115 Uup	ununhexium 116 Uuh	ununseptium 117 Uus	ununoctium 118 Uuo

* Lanthanides	lanthanum 57 La	cerium 58 Ce	praseodymium 59 Pr	neodymium 60 Nd	promethium 61 Pm	samarium 62 Sm	europium 63 Eu	gadolinium 64 Gd	terbium 65 Tb	dysprosium 66 Dy	holmium 67 Ho	erbium 68 Er	thulium 69 Tm	ytterbium 70 Yb
** Actinides	actinium 89 Ac	thorium 90 Th	protactinium 91 Pa	uranium 92 U	neptunium 93 Np	plutonium 94 Pu	americium 95 Am	curium 96 Cm	berkelium 97 Bk	californium 98 Cf	einsteinium 99 Es	fermium 100 Fm	mendelevium 101 Md	nobelium 102 No

Chemical Series of the Periodic Table
Alkali metals	Alkaline earths	Lanthanide	Actinides	Transition metals
Poor metals	Metalloids	Nonmetals	Halogens	Noble gases

How Elements Are Organized
- Groups: Columns of Elements
- Periods: Rows of Elements
Types of Elements
Who Created the Periodic Table?
Images for kids
See also

How Elements Are Organized

The periodic table is arranged in a very specific way. It has rows called periods and columns called groups. This arrangement helps us predict how elements will behave.

Groups: Columns of Elements

The vertical columns on the periodic table are called groups. There are 18 groups in total. Elements in the same group often have similar chemical properties. This means they react in similar ways with other elements. For example, elements in Group 1 (like lithium and sodium) are all very reactive metals.

Periods: Rows of Elements

The horizontal rows on the periodic table are called periods. There are 7 periods. As you move from left to right across a period, the atomic number of the elements increases by one. This means each element has one more proton than the one before it. Elements in the same period do not have similar chemical properties in the same way as groups.

Types of Elements

Elements on the periodic table can be broadly divided into three main types: metals, nonmetals, and metalloids. Each type has different properties.

Metals

Most elements on the periodic table are metals. They are usually shiny, can conduct electricity and heat well, and can be hammered into shapes or drawn into wires. Examples include iron, copper, and gold.

Nonmetals

Nonmetals are found on the right side of the periodic table. They are usually not shiny, do not conduct electricity or heat well, and are often brittle (break easily) or are gases at room temperature. Examples include oxygen, nitrogen, and sulfur.

Metalloids

Metalloids are elements that have properties of both metals and nonmetals. They are found along the zigzag line between metals and nonmetals on the table. Silicon and arsenic are examples of metalloids. They can sometimes conduct electricity, but not as well as metals.

Who Created the Periodic Table?

The periodic table we use today is the result of many years of work by different scientists.

Dmitri Mendeleev

The first widely accepted periodic table was created by a Russian chemist named Dmitri Mendeleev in 1869. He arranged the elements by their atomic weight and noticed patterns in their properties. He even left gaps for elements that had not yet been discovered, and he correctly predicted their properties!

Henry Moseley

Later, in 1913, a British physicist named Henry Moseley improved Mendeleev's table. He discovered that elements should be arranged by their atomic number (the number of protons), not their atomic weight. This solved some problems in Mendeleev's original table and made the patterns even clearer.

Glenn T. Seaborg

In the mid-20th century, an American chemist named Glenn T. Seaborg made important contributions. He discovered many new elements, especially the actinides and transuranic elements. He also suggested a change to the layout of the periodic table, placing the actinide series below the main table, which is how we see it today.

Images for kids

3D views of some hydrogen-like atomic orbitals showing probability density and phase (g orbitals and higher are not shown)
Idealized order of shell-filling (most accurate for   $n$  ≲ 4 .)
Trend in atomic radii
Flowing liquid mercury. Its liquid state at room temperature is a result of special relativity.
Mendeleev's 1869 periodic table
Mendeleev's 1871 periodic table
Dmitri Mendeleev
Henry Moseley
Glenn T. Seaborg
Iron, a metal
Sulfur, a nonmetal
Arsenic, an element often called a semi-metal or metalloid