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

What was the original basis for the periodic table?

  1. Atomic mass

  2. atomic number
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Early versions of the periodic table, such as Mendeleev's, were organized primarily by atomic mass because the concept of atomic number had not yet been discovered.

Multiple choice

Out of 118 elements how many elements are metals and non metals .

  1. 95 metals and 17 non - metals

  2. 93 metals and 20 non - metals

  3. 92 metals and 26 non metals

  4. 100 metals and 18 non metals
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The classification of elements into metals and non-metals is standard in chemistry. While exact counts can vary slightly based on the definition of metalloids, 95 metals and 17 non-metals is a commonly accepted approximation for the 118 elements.

Multiple choice

What is the electron configuration for Ca?

  1. [Ar]4s2

  2. [Ar]4s1

  3. [Kr]4s2

  4. 1s2 2s2 2p64s2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Calcium (Ca) has 20 electrons. The noble gas core [Ar] accounts for 18 electrons, and the remaining 2 electrons occupy the 4s orbital, resulting in [Ar]4s2.

Multiple choice

What are the Elements in Group 1 called?

  1. Alkaline Earth metals

  2. Alkali Metals

  3. Metalloids

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

Group 1 elements are known as the Alkali Metals. They are highly reactive metals with one valence electron.

Multiple choice

What are the elements in Group 2 called?

  1. Alkali Metals

  2. Transition Metals

  3. Alkaline Earth Metals

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

Group 2 elements are known as the Alkaline Earth Metals. They are reactive metals with two valence electrons.

Multiple choice some important compounds of magnesium and calcium the s-block elements chemistry

Which of the following element has $2^{nd} IP<1^{st}IP$?

  1. $Mg$
  2. $Na$
  3. $C$

  4. None
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

All three $Mg$, $C$ and $Ne$ have $2nd$ ionisation potential greater than $1st$ ionisation potential. 

This is the general trend shown by most element that $1^{st} IP<2^{nd} IP<3^{rd} IP<$ and so on.
Hence, option D is correct.