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 the periodic table mendeleef's periodic table mendeleev's periodic law and its limitations mendeleev's periodic table development of the modern periodic table into the history

The Mendeleev's periodic table consists of groups: 

  1. seven

  2. eight

  3. nine

  4. ten
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Eight groups were there in the Mendeleev's periodic table.

Mendeleev divided his periodic table in eight groups and seven periods.

Option B is correct.
Multiple choice chemistry the periodic table mendeleef's periodic table mendeleev's periodic law and its limitations mendeleev's periodic table development of the modern periodic table into the history

Which element was named Eka-aluminium by Mendeleev?

  1. Scandium

  2. Gallium

  3. Germanium

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

Mendeleev predicted the existence of several elements, naming them based on their position relative to known elements. Eka-aluminium was his name for the element that would later be discovered as Gallium.

Multiple choice chemistry the periodic table mendeleef's periodic table mendeleev's periodic law and its limitations mendeleev's periodic table development of the modern periodic table into the history

The basis of periodic law presented by Mendeleev was: 

  1. valency

  2. atomic mass

  3. atomic number

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

He grouped the elements with similar properties and observed that elements were arranged in the increasing order of atomic mass and there was the periodic occurrence of elements with similar properties.

According to this observation, he formulated a periodic law which states:

“the properties of elements are the periodic function of their atomic masses.”

Option B is correct.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

Define element.

  1. Can be broken down by chemical reactions into simpler substances

  2. Cannot be broken down by chemical reactions into simpler substances

  3. Maybe be broken down by chemical reactions into simpler substances

  4. Both b and c
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A pure substance which is made up of only one kind of atom and cannot be broken into two or more simpler substances by physical or chemical means is referred to as an element. An element is homogeneous in nature; it is a pure substance, made up of only one kind of atoms. For example, iron and silver are made of only iron and silver atoms.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

Suppose an orbital may accommodate three electrons then the number of elements in 4th period will be?

  1. 12

  2. 27

  3. 18

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

In the fourth period of periodic table there is filling of 4s,3d,4p orbitals. So the total number of orbitals to be filled $=1(4s)+5(3d)+3(4P)=9$

If each orbital can hold maximum 3 electrons the number of elements$=3\times9=27$
Hence option B is correct answer.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

How many elements is expected in period number 10 of the periodic table?

  1. 68

  2. 72

  3. 50

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

The number of elements in a period is determined by the number of orbitals being filled. For period n, the number of elements is given by 2 * (n+1)^2 / 4 or similar patterns; for period 10, the calculation leads to 72 elements based on the filling of 8s, 5g, 6f, 7d, and 8p orbitals.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

Who defined element as basic form of matter that cannot be broken down into simpler substances by chemical reactions?

  1. Wilhelm Weins

  2. William J. Crooke

  3. Antonie L. Lavoisier

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

Antonie L. Lavoisier defined element as basic form of matter that cannot be broken down into simpler substances by chemical reactions

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

Two elements M and X have electronic configurations 2, 8, 3 and 2, 8, 6 respectively. Identify the correct formula of the compound formed.

  1. MX$ _2$
  2. M$ _2$X
  3. M$ _2$X$ _3$
  4. $M _3$X$ _2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Given that the electronic configuration of X = 2,8,3 and Y = 2,8,6. Thus the valencies they posses to attain noble gas configuration are; X = +3 and Y = -2. Therefore the formula of the compound formed can be written as; $M _{2}X _{3}$.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

The lightest and the most abundant element in the universe is:

  1. zinc

  2. hydrogen

  3. sodium

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

The lightest and the most abundant element in the universe is hydrogen. The percentage of hydrogen in the universe is more than $91$%.


Therefore, hydrogen is the most abundant element in the universe.

Hence, option B is correct.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

The first and last elements of the longest period are ___________.

  1. francium and Uuo

  2. caesium and radon

  3. francium and radon

  4. caesium and Uuo
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Longest period is 6th period. It contains 32 elements. It starts with Caesium. The last element is Radon. 

7th period is not the longest as it contains less than 32 elements.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry
A, B, C are three elements with atomic numbers, Z-1, Z, and Z+1 respectively. B is an inert gas.
Identify the elements having same valence shell.

  1. A, B

  2. B, C

  3. A, C

  4. A, B, C
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Three elements A,B and C. B is a noble gas, A has atomic number 1 less than B and C has 1 more than B. Hence number of valence shell is same in A and B because on adding one electron to Noble gas that is 18 group next electron will occupy, alkali metals group in a next period hence increases in shell number.

Multiple choice evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

Match the atomic number 19, 15, 8, 4 and 2 with each of the following :                                                                                                               

  1. 19: A metal of valency one.

  2. 15: A solid non-metal of period 3

  3. 8: A rare gas

  4. 2: A gaseous element with valency 2.

  5. 4: An element of group 2.
Reveal answer Fill a bubble to check yourself
A,B,E Correct answer