Chemistry

Periodic Classification and Elements

1,092 Questions

Periodic classification organizes chemical elements based on atomic structure, periodic laws, and elemental properties. It covers historical classification systems, electron configurations, and periodic trends. Test takers preparing for chemistry sections will find these questions crucial for mastering fundamental element properties and atomic interactions.

Periodic table structureAtomic orbitalsElement identificationPeriodic laws

Periodic Classification and Elements Questions

Multiple choice chemistry what is inside atom neutrons discovery of neutrons structure of atoms

The atoms of different elements having the same number of neutrons are known as :

  1. isobars

  2. isomers

  3. isotones

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

Two nuclides are isotones if they have same neutron number but different proton number e.g. $boron-12$ and $carbon-13$ both contain 7 neutrons so they are $isotones$.

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

________ element has one electron in the outermost shell and attains duplet configuration after accepting one more electron and attains stability.

  1. Helium

  2. Hydrogen

  3. Lithium

  4. Carbon
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hydrogen has ${ 1e }^{ - }$ in outermost shell, in order to achieve stability either ${ e }^{ - }$ to be removed or added. When added it acquires a stable configuration forming duplet.

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

Hydrogen is the ________ element on the earth.

  1. most abundant

  2. heaviest

  3. lightest

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$H$ is the lightest element on earth as there is only $1$ proton and ${ 1e }^{ - }$. All the other elements have more than 1 electrons and protons along with neutrons.

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

The characteristics of hydrogen resemble the elements of__as well as__groups.

  1. IIA and VA

  2. IIIA and VIA

  3. IIA and VIA

  4. IA and VIIA
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Because hydrogen has ${ 1e }^{ - }$ in its outermost shell which is ready to be donated like that a group $1A$ (alkali metals). Also hydrogen can accept an ${ e }^{ - }$ to from ${ H }^{ - }$ having ${ 2e }^{ - }$ in outer shell which is stable this resembles to $VIIA$ group (Halogen family), as they also require only one ${ e }^{ - }$ to fulfill their incomplete octet.

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

Hydrogen loses its electron to form $H^+$, in this respect, it resembles:

  1. halogens

  2. alkali metals

  3. transition element

  4. alkaline earth metals
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Alkali metals are electro positive in  nature it readily lose its valence shell electron, and hydrogen resembles like alkali metals.

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

The usual valency of hydrogen is:

  1. $-2$
  2. $0$
  3. $+1 $ or sometimes $-1$
  4. $+2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The electronic configuration of hydrogen is ${ 1s }^{ 1 }$ as it has only one electron in its single orbital. So, it can gain one or lose one electron from its s orbital, thereby, showing $+1$ or $-1$ valency.

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

Which group hydrogen has resemblance?

  1. I-A

  2. II-A

  3. IV-A

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

1.Resemblance of H with alkali metals-Both have one electron in its valency shell and form positive ion by losing electron.

2. Resemblance of H with IV group - Both have half filled valence shell. I.P. and E.A of both are comparable.
3. Resemblance of H with VII group- Both have one electron in valence shell and form anion by gaining electron.

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

Hydrogen differs from elements of I-A group as:

  1. hydrogen is gas but others are solid at room temperature

  2. all are metals

  3. hydrogen is a non-metal but others are metal

  4. they donate one electron to become cation
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

Group, I A are alkali metals while hydrogen is considered a nonmetal and hydrogen are in gaseous form while alkali metals are all solids at room temperature like sodium, potassium, etc.


So, the correct options are A and C

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

Hydrogen differs from elements of VII-A group as:

  1. it can gain one electron

  2. it has one electron in its valence shell

  3. its electronic configuration is different from other elements
  4. both $B$ and $C$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hydrogen differs from elements of $VII-A$ group as:


(A) Hydrogen can either share or gain or lose one electron whereas the elements of $VII-A$ group can gain one electron.

(B) Hydrogen has one electron in its valence shell whereas elements of $VII-A$ group have 7 valence electrons.

(C) The electronic configuration of hydrogen is different from the elements of $VII-A$ group.

So, options B and C are the correct answers. 

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

Hydrogen resembles IV-A elements in what respect?

  1. All are metals.

  2. All are non metals.

  3. All are metalloid.

  4. They have half-filled electronic configuration.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

IV A group has half filled valence shell like carbon or silicon and it shares it with the hydrogen singly filled s orbital. They resemble have comparable I.P. and E.A.