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 is the symbol of cadmium?

  1. Cd

  2. Cm

  3. Ca

  4. Cs
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cadmium is a soft, bluish-white metal with atomic number 48. Its chemical symbol is Cd. The other options represent different elements: Cm is curium, Ca is calcium, and Cs is cesium. Cadmium is commonly used in batteries and as a pigment.

Multiple choice

The smallest of all atoms are

  1. Helium atoms

  2. Hydrogen atoms

  3. Oxygen atoms

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

Hydrogen atoms are the smallest because hydrogen has the lowest atomic number (1), meaning it has only one proton and typically one electron. Helium has 2 protons and electrons, oxygen has 8, and uranium has 92. The size of an atom is primarily determined by its number of protons and electron shells.

Multiple choice

Beryllium does not exhibit coordination number greater than 4 because of

  1. non-availability of s orbital

  2. non-availability of p orbital

  3. non-availability of d orbital

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

this option is correct because in electronic configuration of be is 1s22s2 which is not involving d orbitals hence it cannot extend its coordination number more than four as its it not having a d orbital.