Periodic Table

Up to the year 2016, how many elements have been identified on earth?

In 1789, who first divided elements into metals and non-metals?

In which year did Dobereiner propose his Law of Triads?

According to Dobereiner's Law of Triads, the atomic mass of the middle element is approximately—

Which trio did Dobereiner first identify?

Who proposed the Law of Octaves?

According to the Law of Octaves, properties recur with every—

Newlands arranged the elements according to—

In 1869, who published a periodic table grouping elements with similar properties?

Mendeleev's periodic law states that physical and chemical properties of elements recur periodically as—

How many elements did Mendeleev arrange in his table?

Mendeleev's table consisted of—

Mendeleev's correct forecast about the existence of new elements is shown by—

In Mendeleev's table, which element is placed before potassium despite higher atomic mass?

Why is Argon (mass 40) placed before Potassium (mass 39) in Mendeleev's table?

In 1913, who proposed organizing elements by atomic number instead of atomic mass?

The flaw in Mendeleev's table was corrected by Mosley by—

The full form of IUPAC is—

How many elements has IUPAC detected so far?

Lavoisier started with how many elements?

In Mendeleev's table how many elements were detected and how many cells were left blank for undetected ones?

The horizontal rows of the periodic table are called—

The vertical columns of the periodic table are called—

How many periods are there in the modern periodic table?

How many groups are there in the modern periodic table?

All periods of the modern periodic table start at—

The lanthanide and actinide elements are displayed in a small table of—

Lanthanide and actinide elements actually belong to which periods of the main table?

How many elements does period 1 contain?

How many elements does period 2 (or 3) contain?

How many elements does period 4 (or 5) contain?

How many elements does period 6 (or 7) contain?

Group 1 contains how many elements?

Group 2 contains how many elements?

Group 3 (including lanthanide and actinide series) contains how many elements?

Each of the groups 4 to 12 contains how many elements?

Each of groups 13 to 17 contains how many elements?

Group 18 contains how many elements?

Lanthanide elements have atomic numbers ranging from—

Actinide elements have atomic numbers ranging from—

The number of lanthanide elements is—

The number of actinide elements is—

Properties of elements within the same period—

Physical and chemical properties of elements of the same group are—

The period number of an element equals—

The electronic configuration of $\text{Li}(3)$ is—

Lithium belongs to which period?

The electronic configuration of $\text{K}(19)$ is—

Potassium belongs to which period?

According to System 1, if an element's outermost level has only an $s$ orbital, the group number equals—

The element $\text{H}(1)$ with configuration $1s^1$ belongs to which group?

According to System 2, when the outermost level has $s$ and $p$ orbitals, the group number is—

Boron $\text{B}(5)$ with configuration $1s^2 2s^2 2p^1$ belongs to which group?

Nitrogen $\text{N}(7)$ with $1s^2 2s^2 2p^3$ belongs to which group?

Oxygen $\text{O}(8)$ belongs to which group?

Fluorine $\text{F}(9)$ belongs to which group?

Neon $\text{Ne}(10)$ belongs to which group?

According to System 3, when the outermost $s$ orbital is preceded by a $d$ orbital in the inner level, the group number is—

The configuration of $\text{Fe}(26)$ is—

Iron belongs to which group of the periodic table?

Helium $\text{He}(2)$ with $1s^2$ is placed in which group?

Helium's group placement is treated as—

The configuration of $\text{Cr}(24)$ is—

Chromium belongs to which group?

The configuration of $\text{Cu}(29)$ in the outer level is—

Copper belongs to which group?

The element with configuration $1s^2 2s^2 2p^6 3s^2 3p^6 3d^2 4s^2$ belongs to—

Sodium $\text{Na}(11)$ belongs to—

Magnesium $\text{Mg}(12)$ belongs to—

Aluminium $\text{Al}(13)$ belongs to—

Silicon $\text{Si}(14)$ belongs to—

Phosphorus $\text{P}(15)$ belongs to—

Sulphur $\text{S}(16)$ belongs to—

Chlorine $\text{Cl}(17)$ belongs to—

Argon $\text{Ar}(18)$ belongs to—

Calcium $\text{Ca}(20)$ belongs to—

Scandium $\text{Sc}(21)$ with $3d^1 4s^2$ belongs to—

Titanium $\text{Ti}(22)$ belongs to which group?

Vanadium $\text{V}(23)$ belongs to which group?

Manganese $\text{Mn}(25)$ belongs to which group?

Cobalt $\text{Co}(27)$ belongs to which group?

Nickel $\text{Ni}(28)$ belongs to which group?

Zinc $\text{Zn}(30)$ belongs to which group?

Elements having the same electron arrangement in their outermost orbit belong to—

Elements with different outer-shell configurations belong to—

Elements with one electron in the outermost shell tend to—

The reaction $\text{Na}(1s^2 2s^2 2p^6 3s^1)\rightarrow \text{Na}^+(1s^2 2s^2 2p^6) + e^-$ shows that Na—

Elements with seven electrons in the outermost shell tend to—

The reaction $\text{Cl}(1s^2 2s^2 2p^6 3s^2 3p^5) + e^- \rightarrow \text{Cl}^-(1s^2 2s^2 2p^6 3s^2 3p^6)$ illustrates—

The main basis of the modern periodic table is—

Group 2 elements all have an outer configuration ending in—

Group 1 elements (excluding H special case) all have an outer configuration ending in—

Hydrogen is placed in Group 1 because—

Hydrogen also shows similarity with which group?

Although Hydrogen can also accept an electron like halogens, it is finally placed in Group 1 because—

Helium has the configuration $1s^2$ but is placed in Group 18 because—

Group 2 elements are called—

Lanthanide and actinide elements are placed below the main table—

Which property is typical of metals?

According to modern definition, metals are elements that—

The tendency to donate electrons is called—

The reaction $\text{Li}\rightarrow \text{Li}^+ + e^-$ shows—

In any period, metallic character—

Non-metallic elements are characterized by—

Non-metallic property in a period—

Elements that sometimes donate and sometimes accept electrons are—

Which is an example of a sub-metal?

In the periodic table, sub-metals are mostly found in the—

As we move from left to right in a period, the atomic radius—

The reason atomic radius decreases across a period is—

As we move down a group, the atomic radius—

New shells added on going down a group—

Which has the smallest atomic radius?

Among Li, Na, K, Rb, Cs, Fr in Group 1, which has the smallest atomic radius?

Ionization energy is the energy required to—

As atomic radius decreases, ionization energy—

Among Na, Mg, Al, Si — which has the greatest ionization energy?

Among Na, Mg, Al, Si — which has the least ionization energy?

Among Group 1 alkali metals (Li, Na, K, Rb, Cs, Fr), which has the highest ionization energy?

Among Group 17 elements (F, Cl, Br, I, At), which has the highest ionization energy?

In a group, going from top to bottom, ionization energy—

Electron affinity is the energy—

As atomic radius decreases, electron affinity—

Among Be, Ca, Sr, Ba, Mg, Ra — which has the highest electron affinity?

Among Be, Ca, Sr, Ba, Mg, Ra — which has the lowest electron affinity?

Among Na, Mg, Al, Si of period 3 — which has the highest electron affinity?

Among Na, Mg, Al, Si of period 3 — which has the lowest electron affinity?

Electronegativity is the attraction by an atom for the shared electron pair in—

As the atomic radius decreases, electronegativity—

In period 3, which atom has the lowest electronegativity?

In period 3, which atom has the highest electronegativity?

Generally, when the size of an atom is small—

Apart from Hydrogen, the six elements of Group 1 are called—

Why are Group 1 elements (except H) called alkali metals?

Group 2 elements are called alkaline earth metals because—

Which of the following is an alkaline earth metal?

Coin metals belong to which group?

Which of the following are coin metals?

Why are Cu, Ag, Au called coin metals?

The element X is used to symbolise—

Halogens belong to which group?

The meaning of "Halogen" is—

Halogens form di-atomic molecules by—

Which set lists halogens?

The main natural source of halogens is—

Group 18 elements are called—

Inert gases do not show tendency to react because—

Which of the following is NOT an inert gas?

Inert gases at normal temperature exist as—

Transition elements belong to which block of the periodic table?

Which is true of transition elements?

Transition elements typically show—

Which of the following is a transition element?

If 4 physical and 4 chemical properties are considered for 118 elements, the total number of properties is—

Knowing the common properties of each group enables us to know the properties of—

The periodic table gave prior idea about elements that—

The reaction $\text{H}_2(g) + \text{Cl}_2(g) \rightarrow 2\text{HCl}(g)$ shows that hydrogen reacts with halogens to produce—

Dissolving HCl gas in water produces—

The reaction $\text{CaCO}_3 + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} + \text{CO}_2$ shows that hydrohalide acids react with carbonates to produce—

The reaction $\text{H}_2(g) + \text{F}_2(g) \rightarrow 2\text{HF}(g)$ produces, on dissolution in water—

Magnesium carbonate reacts with dilute HCl to produce—

Calcium carbonate and dilute HCl produce—

Carbon dioxide gas can be identified by—

When excess CO$_2$ is passed through cloudy lime water, the cloudiness clears because—

In the laboratory preparation of CO$_2$, why must the end of the thistle funnel be kept submerged in water?

CO$_2$ collects at the bottom of a gas jar because—

In the experiment, calcium carbonate can be substituted by—

Hydrochloric acid in the experiment can be substituted by—

The element with configuration $1s^2 2s^2 2p^6 3s^2 3p^6 3d^3 4s^2$ belongs to which group?

An element X is in period 4, group 1 (configuration ends with $4s^1$). Element Y is in period 5, group 1. Both have—

Going from X (period 4, Group 1) to Y (period 5, Group 1), atomic radius—

Of two Group-1 elements at periods 4 and 5, the more reactive one is—

An element with atomic number 12 (X), 20 (Y), 24 (Z) — which two are in the same group?

From the same stem (X = 12, Y = 20, Z = 24): the position of Z is—

X (Z = 12) and Y (Z = 20) exhibit similar chemical properties because—

Why is sodium called an alkali metal?

Why is barium called an alkaline earth metal?

Between Ca and Mg, which has higher ionization energy?

Why is Si called a metalloid (sub-metal)?

In a fragment of the periodic table, period 3 has elements X (Group 1) and Y (Group 2), period 4 has A (Group 17) etc. Which has the highest electron affinity in the stem?

Among elements of period 3 to the period 4 along Group 1 to 17, ionization energy generally—

The trend "atomic radius decreases left to right, electronegativity increases left to right" together explains why—

Why is helium not placed in Group 2 of the periodic table?

The "Modern Periodic Law" states properties of elements are a periodic function of—