Chemistry · Science General

Periodic Table and Elements

421 Questions

The periodic table and elements questions test knowledge of chemical properties, atomic structures, and periodic trends. Topics include alkali metals, transition elements, and ionisation potential. These concepts frequently appear in general science sections of competitive examinations.

Alkali metals propertiesTransition elementsLattice energyIonisation potentialAlkaline earth metals

Periodic Table and Elements Questions

Multiple choice chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

Sodium reacts with water more vigorously than lithium because it :

  1. has higher atomic weight.

  2. is a metal.

  3. is more electropositive.

  4. more electronegative.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sodium reacts with water more vigorously than lithium its more electropositive and will give electrons easily.
Hence option C is correct.

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Hydorgen forms binary compounds called hybrides with several elements in the periodic table.Regarding these hydrides the wrong statement 

  1. Among lanthanoids europioum and ytterbium form ionic hydrides

  2. Density of ionic hydrides is less while the density of interstitial hydrides is more than the metals from which they are formed

  3. The rate of reaction of alkali metals towards hydrogen decreases from lithium to ceasium

  4. Hydrogen gas can be purified by the phenomenon of Occlusion of hydrogen by palladium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Europium and Ytterbium are lanthanoids that form non-stoichiometric or interstitial hydrides, not ionic hydrides. The other statements are generally accepted chemical facts regarding hydrides.

Multiple choice chemistry combustion structure of flame flame combustion, fuels and flame

A lilac-coloured flame is produced on heating.

  1. Potassium in a flame

  2. Cobalt in a flame

  3. Sodium in a flame

  4. Methane in oxygen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Potassium on heating produced lilac-colured flame because on heating, an atom entities its electrons and they jump to higher energy levels. When the electron return to lower energy levels, they emit energy in the form of light. The colour produced on heating depends upon wavelength of emitted light.
Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

Identify the incorrect statement among the following. 

  1. 4f and 5f orbitals are equally shielded.

  2. 4-Block elements show irregular and erratic chemical properties among themselves.

  3. La and Lu have partially filled d-orbitals and no other partially filled orbitals.

  4. The chemistry of various lanthanoids is very similar.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

4f and 5f orbitals are not equally shielded. 5f are poorly shielded as 5f orbitals are away from the nucleus.

Also, 5f has poor shielding effect than 4f due to the large size of f-orbital, it is more diffused.

Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

Which of the following is not an actinoid ?

  1. Am

  2. Cm

  3. Fm

  4. Tm
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

LANTHANIDES


58Ce  59Pr  60Nd  61Pm  62Sm  63Eu  64Gd  65Tb  66Dy  67Ho  68Er  69Tm  70Yb  71Lu 

ACTINIDES

 90Th 91 Pa 92 U 93 Np 94 Pu 95 Am 96 Cm 97Bk  98Cf  99Es  100 Fm 101 Md 102No  103Lr 
          
Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

Actiniod contraction is more than lanthanold contraction because:

  1. energy of 4f and 5f orbitals are same

  2. 5f orbitals are more diffused as compared to 4f orbitals

  3. actinoids show greater range of oxidation states than lanthanoids

  4. actinoids are highly reactive
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$5f$ orbitals are bigger than $4f$ orbitals, in other words, $5f$ orbitals are more diffused thereby having the poor shielding effect. Hence have a more effective nuclear charge thereby having a small size. Hence actinide contraction is more than lanthanide contraction.

Multiple choice chemistry d- and f-block elements actinoids the actinoids the d-and f-block elements comparison of lanthanoids and actinoids

Beryllium resembles Aluminium in properties. This is mainly due to:

  1. equal electro negativity values of elements

  2. equal atomic volumes of the elements

  3. equal electron affinity

  4. equal nuclear charges in their atoms
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Beryllium resembles Aluminium in properties. This is due to similar electronegativity, similar atomic size and they diagonal relationship.

Multiple choice chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

Which of the following shows least melting point?

  1. $Be$
  2. $Mg$
  3. $Ca$
  4. $Sr$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ans : $B$ $\rightarrow$ $Mg$

Generally melting point of the metals decreases down the group. But $Mg$ has anomalously low melting point in group $2$.
Group $2$ metals have metallic bonding. If we look at the crystal structure, $Be$ & $Mg$ are hexagonal close packed, $Ca$ & $Sr$ are face centered cubic.
At melting point, $Be$, $Ca$ and $Sr$ are body centered where as $Mg$ is hexagonal closed packed. Due to this arrangement, $Mg$ shows least melting point

Multiple choice chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

In which case first has lower melting point than second?

  1. Mg, Be

  2. Be, Ca

  3. Cs, Li

  4. K, Li
Reveal answer Fill a bubble to check yourself
A,C,D Correct answer
Explanation

(A) The melting point of magnesium is 924 K which is lower than the melting point of beryllium which is 1560 K.
(B) The melting point of beryllium is 1560 K which is higher than the melting point of calcium.
(C) The melting point of cesium is 302 K which is lower than the melting point of lithium which is 454 K.
(D) The melting point of potassium is 336 K which is lower than the melting point of Li which is 454 K.

Multiple choice chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

In which case second has lower boiling point than first?

  1. Li, K

  2. Be, Mg

  3. Li, Cs

  4. Ca, Mg
Reveal answer Fill a bubble to check yourself
A,B,C,D Correct answer
Explanation

(A) The boiling point of K is $1032$ K which is lower than that of Li ($1615$ K)
(B) The boiling point of Mg is $1363$ K which is lower than that of Be ( $2745$ K).
(C) The boiling point of Cs is $944$ K which is lower than that of Li ($1615$ K).
(D) The boiling point of Mg is $1363$ K is which is lower than that of Ca ($1767$ K).
Hence, all are correct.