Chemistry

Periodic Classification and Elements

1,176 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 classification of elements- the periodic table introduction to periodic table necessity of classification need for classification

Classification of elements are done on the basis of ___________.

  1. atomic number

  2. atomic weight

  3. valency

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

Based on the modern periodic law, the elements are arranged into rows and columns based on their atomic number. There are 18 columns, called groups and 7 rows, called periods. 

Multiple choice chemistry classification of elements- the periodic table introduction to periodic table necessity of classification need for classification

The physical properties of elements changes according to_____________.

  1. classification of elements in groups and periods

  2. classification of elements in groups

  3. classification of elements in periods

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

The physical properties (notably, melting and boiling points) of the elements in a given trend in vary from group to group and from period to period.


Hence the correct option is A.

Multiple choice chemistry atomic theory, periodic classification and properties of elements introduction to periodic table necessity of classification need for classification

Transition elements are also known as ____________.

  1. $d$ - block elements
  2. $f$ - block elements
  3. $s$ - block elements

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

The transition elements are also known as the $d$-block elements because while the outermost level contains at most two electrons, their next to outermost main levels have incompletely filled $d$ sub-orbitals, which are filled-up progressively ongoing across the periodic table from $8$ to $18$ electrons. The filling of the $d$ sub-orbitals of the transition elements across a row of the periodic table is not always regular.


Hence, the correct option is $\text{A}$

Multiple choice chemistry atomic theory, periodic classification and properties of elements introduction to periodic table necessity of classification need for classification

Based on modern classification of periodic table atomic number increases on moving from _________ in periodic table.

  1. left to right

  2. right to left

  3. straight

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

Elements in the same period tend to have shared chemistry and exhibit a  trend in properties with increasing atomic number from left to right.

Multiple choice chemistry atomic theory, periodic classification and properties of elements introduction to periodic table necessity of classification need for classification

The modern periodic table is most_________ form of periodic table.

  1. insignificant

  2. Significant

  3. Both A and B

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

In the standard periodic table, the elements are listed in order of increasing atomic number. Thus, it is relatively easy to predict the chemical properties of an element if one knows the properties of the elements around it i.e. it is more significant form of periodic table.

Multiple choice chemistry atomic theory, periodic classification and properties of elements introduction to periodic table necessity of classification need for classification

Significance of classification of periodic table is to ___________.

  1. predict the blocks of elements

  2. predicts the groups of elements

  3. both A and B

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

Periodic classification of elements is the method by which elements are grouped on the basis of their characteristics. Classification of elements in groups provide us a fixed pattern in which the elements change their properties periodically. Periodic table made the study of physical and chemical properties of elements simple and organized.

Multiple choice chemistry classification of elements- the periodic table introduction to periodic table necessity of classification need for classification

Classification of periodic table based on atomic number is given by:

  1. Mendeleev's

  2. Mosley

  3. Both A and B

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

Henry Moseley found a relationship between the X-ray wavelength of an element and its atomic number. Moseley's discovery showed that atomic numbers were in fact based upon experimental measurements.

Multiple choice chemistry atomic theory, periodic classification and properties of elements introduction to periodic table necessity of classification need for classification

Lanthanoids are also called as ___________.

  1. Transition elements

  2. Rare earth elements

  3. Both A and B

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

Rare earth metals are a group of chemically similar metallic elements comprising the lanthanide series and (usually) scandium and yttrium. They are not especially rare, but they tend to occur together in nature and are difficult to separate from one another.

Multiple choice chemistry atoms, molecules and radicals molecular formula and valency valency and chemical formulae combining capacity and chemical formulae

The molecular formula is a short form representation of

  1. A compound

  2. An element

  3. A mixture

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

 A chemical formula that shows the total number and kinds of atoms in a molecule, but not their structural arrangement or the molecular formula is a short form representation of a compound.

Multiple choice chemistry atoms, molecules and radicals molecular formula and valency valency and chemical formulae combining capacity and chemical formulae

When naming a binary compound, what determines the prefix for an element in a compound?

  1. The number of atoms of that element in the compound

  2. The number of valence electrons in the element

  3. The total number of atoms in the compound

  4. The number of shared electrons in the compound

  5. The number of different elements in the compound
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When naming a binary compound, the number of atoms of that element in the compound determines the prefix for an element in a compound.
For example, while naming  $N _2O _3 $, the prefix di is used for $N$ which indicates $2 N$ atoms and the prefix tri is used for $O$ which indicates $3 O$ atoms. Hence, the name dintirogen trioxide.

Multiple choice chemistry atoms, molecules and radicals molecular formula and valency valency and chemical formulae combining capacity and chemical formulae

Predict the formula of stable compound formed by an element with atomic number 114 and fluorine.

  1. $AF _{3}$
  2. $AF _{2}$
  3. $AF$
  4. $AF _{4}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Element A with atomic number 114 will share four electrons to attain stable noble gas electronic configuration. It falls in the Carbon family.

Fluorine shares one electron to attain stable noble gas electronic configuration. One atom of A combines with four atoms of F to form $AF _4$.

Hence, the correct option is $\text{D}$
Multiple choice chemistry the periodic table newland's law of octaves development of the modern periodic table into the history

Law of octaves stated :

  1. every eighth element had properties similar to the first element

  2. every third element had properties similar to the first element

  3. the properties of the middle element were in between the other two members

  4. the properties of the elements were repeated after regular intervals of 3,4 or 8 elements
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Newland's Law of octaves stated that if elements (known at Newland's time) were arranged in increasing order of their atomic weights, every eighth element had properties similar to the first element. For example, Li and Na have similar properties.

Multiple choice chemistry the periodic table newland's law of octaves development of the modern periodic table into the history

If X and Y are two elements which belong to same group of Newland's periodic table, how many elements exists between X and Y?

  1. $4$
  2. $5$
  3. $6$
  4. $7$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In Newland's periodic table, $1$st element and the $8$th element have the same chemical property, i.e., they belong to the same group. So, the table will look like:
$\begin{equation}X\;1\;2\;3\;4\;5\;6 \ Y\end{equation}$
So, there are $6$ elements between X and Y.

Multiple choice chemistry the periodic table newland's law of octaves development of the modern periodic table into the history

Dobereiner grouped the elements into triads and Newland gave the:

  1. law of Octaves

  2. mass number

  3. atomic number

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

In 1864 newlands in chemistry, the generalization made by the English chemist J.A.R. Newlands in 1865 that, if the chemical elements are arranged according to increasing atomic weight, those with similar physical and chemical properties occur after each interval of seven elements. Newlands was one of the first to detect a periodic pattern in the properties of the elements and anticipated later developments of the periodic law. Hence called law of octaves.