UNIT#11 s AND p BLOCK ELEMENTS Flashcards
Which of the following represent elements in order o decreasing atomic size?
Li, Be, b
Which of the following will remain constant along the period?
Shell Number
The correct order of atomic radii is:
F
Increase in atomic size down the group is due to
➡Addition of shells
➡Shielding Effect
Atomic radius of fluorine is only larger than ____ in its period.
Ne
Which one of the following is smallest in size?
Na+
Consider the iso-electronic species, K+,S-2,Cl- and Ca+2, the radii of the ion decrease as:
S-2>Cl-1>K+>Ca+2
The radius of fluorine atom is 72pm and that of the fluoride ion(F-) is:
133pm
One of the following species is iso-electronic with Ca+2. Which is that:
Ar
The radii of H, H+ and H- are in the order of:
H->H>H+
The ionization energy of an element is:
The energy required to remove the outermost electron of an atom of the element
The 1st ionization energy of metal is lower and 2nd ionization energy is high, it indicate that group number is;
IA
The greater 1st ionization energy would be associated with which of the following configuration:
1s2, 2s2 2p6
Which one of the following series is arranged in order of increasing value:
The first ionization energies: Oxygen, Fluorine, Neon
In the periodic table, the ionization energy of elements of decreases from top to bottom because of:
Increase in atomic size
In the following, the element with the highest ionization energy is:
[Ne] 3s2 3p3
Due to extra stability of half-filled orbital
The unit of ionization energy is;
KJ/mol
Which of the following is NOT true about electronegativity?
➡Metal has electronegativty less than 2❌
➡With increase in Oxidation state, Electronegativity decreases✅
➡It has not unit❌
➡It determines the polarity of molecule❌
The power of an atom to attract shared pair of electrons towards itself in a molecule is called:
Electronegativity
ElectronegativityWhich one of the following periodic properties has no unit:
Electronegativity
Which statement is correct?
➡Loss of valence electron may lead to loss of valence shell
➡Radius of isoelectronic ions decrease left to right in 3rd period
➡Anionic radius increase with magnitude of negative charge
Which of the following element has greater negative first electron affinity?
C
Which of the following group of elements have positive 1st electron affinity
I
Melting points of group Iia elements are considerably higher than those of group IA elements because:
IIA provide more binding electron
The lowest melting point among these four elements is of:
Mg
The highest melting point among these elements is of:
Nitrogen
Generally the melting point decreases from VA to VIIIA along the period but with the exception of;
Sulphur
Among the given elements of period 3, the highest value of melting point is observed:
Si
Correct oder of melting point of group IIA elements
Be>Ca>Mg
In which group melting and boiling point decreases down the group:
IA
The element which has boilng point less than 0C is:
Nitrogen
Which of the following is incorrect information;
➡Metals have free electrons in the valence shell
➡Electrical conductivity of metals increases with the increases of temperature
➡Metalloids are poor conductors of electricity
➡Non-metals have atomic conductance usually less than 10^-10 ohm-1
Which of the following group of elements have extra ordinary high value of electrical conductivity
IB
Coinage matals➡Cu,Ag,Hg
Which one of the following alkali metals orms only normal oxide when it reacts with O2;
Lithium
The elements of group I-A react violently with water and make the solution
Alkaline
What is the nature of reaction Li2O + H2O➡2LiOH
Acid-base
Which of the following metal can form peroxide with oxygen;
Ba
Which one of the following doesn’t react with water even at red hot temperature:
Be
Addition of second electron to a uni-negative ion always:
Endothermic Process
Calcium and Magnesium react with ______ to for hydrogen gas
Dilute Nitric acid
Shells in calcium are:
4
In M shell, which sub-shells are present:
➡s
➡p
➡d
When Al is burnt in air fame produced will be:
White
Choose the most basic oxide:
Na2O
Gypsum is applied to the soil as a source of:
➡Ca
➡S
The _____- study of compoisition of pure substance in 17th century clearly shows that few elements are components of many substances;
Quantitative
In periodic table, the period number tells the:
Number of shell
The ionic radius of an ion is the radius of the ion while considering it to be ____ in sample.
Spherical
Sodium is not observed in +2 oxidation state because of its:
High second ionization potential
Electron afinity of an atom is the energy released when an electron _____ to an empty or partially filled orbital of an atom to form:
➡Added
➡Cation
By increasing which of the following factor polarizability increases?
Atomic Radius
Which of the following faily is linked with plant ashes?
Alkali metals
Which ion will have a maximum value of the heat of hydration?
Al+3
Covalent chracter of hydrides decrease___?
Down the group
Which one is an index to metallic character?
Ionization Energy
Which one of the following carbonate is water-insoluble?
CaCO3
Due to formation of protective layer of oxides at aluminium oxide surface, it is hard to burn it:
Completely in oxygen
Crystals of Na2Co3.10H2O when exposed:
➡Lose water
➡Remain solid
Ionziation energies of atoms depends upon the factors:
➡Atomic Radius of atoms
➡Shielding effect of inner electrons
➡Nature of orbital
Alkali means:
Ash
As far as nuclear charge increases, the decrease in ionic radii will also;
Large
Which of the following element has highest electronegativity?
Fluorine
The msot common positive ions are formed by the atoms:
Metals
The shielding effect is also called:
Screenng effect
Size of molecule depends on:
➡No. of atoms
➡Shape of atoms
➡Nature of atom
Energy required to remove an electron from gaseous neutral atom is:
Ionization Energy
The elements for which the value of ionization energy is low can:
Lose electron readily
Which one remaisn same along a period?
Numebr of shells(orbits)
More the ionization energy of an element
Less the metallic character
Along a period ,atomic radius decreases. This gradual decrease in radius is due to;
Increase in number of protons in the nucleus
What is the trend of melting and boiling points of the elements of short periods as we move from left to right in a periodic table?
Melting and Boiling Points first increase then decrease
Arrange the following elements according to the trends of ionization energies C,N,Ne,B
B
Keeping in view the size of atoms, which order is correct?
Li>Be
Which one of the following will have the smallest radius?
Si+4
The ionic radius of fluoride ion is;
136pm
Ionic radius along the period decreases due to;
Increase in nuclear charge
Down the group acid-base behaviour of metalic oxides of group 2 elements changes to:
More basic
In period 2 and period 3 maximum melting point shown by elements:
➡Carbon
➡Silicon
The strongest acid among the following is:
HI
When the elements of group 2A are exposed to air, they quickly become coated with the layer of oxide. What is the purpose of this oxide layer
The oxide layer protects the metal from further attack
Alkaline earth metal hydroxides decompose on heating. Which of the following reactions is a correct representation of this decomposition?
M(OH)2 ➡MO2 + H2O
Melting points of group II-A elements are higher than those of group I-A because;
Atoms of II-A elements provide two binding electrons
Among the following, which one is least reactive metal:
Be
Melting point of Na & Mg decreases down the group due to:
Increment in size
Which element has the highest electron affinity among halogens?
Cl
Which one of the following properties decreases across the third period of elements in the periodic table?
Ability to act as reducing agent
In the 3rd period of the periodic table which of the following property is decreasing consistently?
Atomic Radius
In the third period of elements, there lies of element “X” which is metallic in nature and it can reduce chlorine gas rapidly. To which group of elements does “X” belong:
IA
THe hydration energy of Mg+2 is less than
Al+3
Which alkaline earth metal makes peroxides?
Ba
Lithium reacts with air to form:
➡Li2O
➡Li3N
How many elements are there in the 3 period of periodic table?
8
Which oxides of “K” contain more oxygen than is normal oxide?
Super Oxide
Modern periodic table is arranged in acending order of:
Proton Number
ionization energy decreases down the gorup from top to bottom due to;
Increase in shielding effect of the interveing electrons
Oxidation number o aprticular element can be directly or indirectly inferred from its;
Group Number
Potassiuum, Rubidium, Cesium reacts with oxygen to form which types of oxides?
Superoxides
Magnesium reacts with nitrogen to form:
Mg3N2
Densitites of alkali metals are low due to;
Large atomic volume
Which of the following statements is incorrect?
➡Among halogens chlorine has maximum electron affinity❌
➡Along the period M.P and B.P increases upto IVA group❌
➡Among Be, B, C and N, the Be element has minimum ionization energy value✅
➡Cs is the most electropositive and F is the most electronegative element❌
Which of the followign groups show abnormal trends in electron affinity values:
➡IIA
➡VA
➡VIIIA
Shielding effect across a third period:
Remains same
While moving down a group in the periodic table, which of the following would not be true:
➡All the atoms have the same number of valence electrons❌
➡Electronegativty decreases❌
➡Atomic size increases❌
➡Metallic character decreases and the basic nature of their oxides decreases✅
Mark the correct statement:
Melting points of halogens increase down the group
Electronic configuration of alkali metals is:
ns1
Carbonate of ___ is least soluble in IA group.
Li2CO3
One of the following will form superoxide when burnt in air
K
Which among the alkali metals does not react with C2H2:
Li
Which of the following compound is least soluble in water;
Mg(OH)2
Which of the following show -1 oxidation state of in its oxides, formed by its reaction with O2 at 600°C
Ba
On moving down the group in metals, reactivity of metals:
Increases
M + O2 ➡MO2. The metal M is;
Ba
The gas evolved when Ca reacts with boiling water is;
H2
Which IIA metal will not form normal oxide in air at 600°C
Ba
Which alkaline earth metal liberates hydrogen when treated with NaOh
Be
Which one of the following metal of 3rd forms only peroxide when it reacts with O2;
Sodium
Sodium and Magnesium form oxide with oxygen;
Basic Oxide
Which one of the following from 3rd period doesn’t react with water
Ar
The correct order of ionic radius is:
N-3>O-2>F-
Select the correct option according to size:
➡Mg+ > Mg+2
➡Ca+ > Ca+2
➡Be+2 < Be+1
Which atom has the smallest size?
He
First electron affinity is maximum for:
Chlorine
The relative attraction of the nucleus of an atom for the electrons in a chemical bond is:
Electronegativity
Which of the following shows minimum electrical conductance:
Na
Which ion is not formed in water:
➡H-
➡O-2
Three elements A,B,C have consecutive proton numbers, if B is a noble gas, which of the following statement about these elements is not correct:
➡A can have variable oxidation states❌
➡A has high electron affinity whereas C has low ionization potential❌
➡A and C will form covalent bond with each other✅
➡A is a non-metal and C is a metal❌
Which of the followings will have zero oxidation state?
VIIIA
Which statement is incorrect?
➡All the metals are good conductor of electricity❌
➡All the metals are good conductor of heat❌
➡All the metals form positve ions❌
➡All the metals form acidic oxides✅
Coinage metals of ____ group have extraordinary high values of electrical conductance
IB
The elements placed in the extreme right periodic table are:
Non-Metals
In alkali metal which one is a best conductor of electricity?
Cs
Which of the following oxide is most basic among alkali metals.
K2O
Ionization energy o group IA is minimum for:
Cs
I.E decreases down the group
One of the followign is least reactive among following:
Li
Lithium shows diagnol relationship with which of the following element
Mg
Lithium is only Group IA metal which combines with nitrogen and carbon to fomr:
➡Lithium Nitride
➡Lithium Carbide
Which oxide of IIA metal is most stable:
BeO
Which oxide of IIA dissociate into ions in water, most easily:
BaO
Which of the followings is not purely base:
BeO
Reaction of alkaline earth metals with O2 is:
Oxidation
Magnesium burns in air to form:
➡MgO
➡Mg3N2
The elements of period 3rd react violently with water and make the solution
➡Alkaline
➡Acidic
➡Amphoteric
Which of the following pair does not react directly with oxygen?
➡Cl
➡Ar