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

The principal quantum number is related to the

  1. size of the orbital

  2. orientation of the orbital in space

  3. orbital angular momentum

  4. spin angular momentum

  5. -
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The principal quantum number 'n' represents the relative overall energy of each orbital and the energy of each orbital increases as the distance from the nucleus increases.

Multiple choice

Atoms of an element differ from atoms of all the other elements in

  1. atomic number and electronic configuration

  2. atomic number and number of valence electrons

  3. number of neutrons and electronic configuration

  4. number of neutrons and number of valence electrons
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Atoms of an element differ from atoms of all the other elements in atomic number and electronic configuration.

Multiple choice

What is the maximum number of electrons present in N-shell?

  1. 8

  2. 18

  3. 64

  4. 32
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The maximum number of electrons that can occupy a specific energy level can be found using the following formula: Electron Capacity = 2n2 Thus, maximum number of electrons in N-shell will be = 2 x 42 = 32

Multiple choice

Atom is the ________part of an element.

  1. biggest

  2. largest

  3. smallest

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Atoms are the smallest particles that retain the chemical properties of an element. They consist of electrons orbiting a nucleus containing protons and neutrons. Atoms combine to form molecules but are themselves the fundamental units of matter.

Multiple choice

_____________ contain unpaired number of electrons.

  1. Diamagnetic materials

  2. Paramagnetic materials

  3. Ferromagnetic materials

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

Paramagnetic materials have a small, positive susceptibility to magnetic fields. These materials are slightly attracted by a magnetic field and the material does not retain the magnetic properties when the external field is removed. Paramagnetic properties are due to the presence of some unpaired electrons.

Multiple choice

Which is the symbol of ' Barium element'?

  1. Br

  2. B

  3. Ba

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

Barium is a chemical element with symbol Ba and atomic number 56. 'Br' is Bromine, 'B' is Boron. Barium gets its name from the Greek word 'barys' meaning heavy, as it's a dense alkaline earth metal. The symbol Ba comes from its Latin name 'Baryta'.

Multiple choice

What are transition elements?

  1. The elements having 2 outermost shells incomplete.

  2. The elements having 3 outermost shells incomplete.

  3. The elements having the outermost shell full.

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, it is correct, they have the 2 outermost shells incomplete and valence electrons are available from them. They are also called d block elements.The three long periods 4th ,5th,6th periods come in this.

Multiple choice

Why some gaps are seen in Mendeleev's periodic table?

  1. He predicted the existence of some elements and space was left for them.

  2. It showed gaps between the atomic weight of elements in a continuous manner.

  3. Space was left for isotopes and nobel gases.

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

It is correct because Mendeleev was able to predict the existence and even properties of some elements and so he left space for them in the periodic table.

Multiple choice

Which period is incomplete in the periodic table?

  1. First period

  2. Second period

  3. Seventh period

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

Yes, it is correct. It starts with element Francium. This period contains the heaviest element which occurs naturally on earth, uranium. Most of the subsequent elements in this period have been synthesized artificially and on many  elements of this period work is still going on in the lab.  All elements are radioactive in this period.

Multiple choice

Which of the following statements is/are incorrect?

(a). Atoms of most elements are able to exist independently. (b). Atoms form molecules and ions. (c). An atom is a group of molecules tightly held together by attractive forces.

  1. (a) only

  2. (b) only

  3. (c) only

  4. (a) and (b)

  5. (a) and (c)
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct answer as both these statements are incorrect. Atoms of most elements are not able to exist independently. A molecule is, in general, a group of two or more atoms that are chemically bonded together, i.e. tightly held together by attractive forces.

Multiple choice

Which of the following is / are true regarding the properties of elements in a group? (a) Electropositive character increases, moving from top to bottom. (b) Atomic radius decreases, moving from top to bottom. (c) Valence electrons increase, moving from top to bottom. (d) Number of shells remains the same moving from top to bottom.

  1. only a

  2. both a and b

  3. both b and c

  4. both c and d

  5. a, b and c
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, it is correct. Only a is correct. Atomic radius increases, the number of valence electrons remains the same and the number of shells increase, while moving from top to bottom in a group.