(English Medium) ICSE Class 9 - CISCE Question Bank Solutions for Chemistry

From the symbol `""_12^24"Mg"`
, state the mass number, the atomic number and electronic configuration of magnesium.

Sulphur has an atomic number 16 and a mass of 32.

State the number of protons and neutrons in the nucleus of sulphur. Give a simple diagram to show the arrangement of electrons in an atom of sulphur.

Draw the orbital diagram of `""_20^40"Ca"^(2+)` ion and state the number of three fundamental particles present in it.

Elements X, Y and Z have atomic numbers 6, 9 and 12 respectively. Which one:

1. Forms an anion
2. Forms a cation
3. Has four electrons in its valence shell?

From the symbol `""_2^4"He"`  for the element helium, write down the mass number and the atomic number of the element.

An atom of an element has two electrons in the M shell.

What is the (a) atomic number (b) number of protons in this element?

Give reason

Actual atomic mass is greater than mass number.

An element A atomic number 7 mass numbers 14
B electronic configuration 2,8,8
C electrons 13, neutrons 14
D Protons 18 neutrons 22
E Electronic configuration 2,8,8,1

State Valency of each element

An element A atomic number 7 mass numbers 14

B electronic configuration 2,8,8

C electrons 13, neutrons 14

D Protons 18 neutrons 22

E Electronic configuration 2,8,8,1

State (i) Valency of each element (ii) which one is a metal (iii) which is non-metal (iv) which is an inert gas

What is meant by the 'atomic number of an element'?

Match the atomic numbers 4,8,10,15 and 19 with the following:

Element which can form trivalent ion

Match the atomic numbers 4,8,10,15 and 19 with the following:

Element with four shells

Match the atomic numbers 4,8,10,15 and 19 with the following:

Element with 6 valence electrons

Match the atomic numbers 4,8,10,15 and 19 with each of the following:

An element which does not form ion 

Elements X, Y and Z have atomic numbers 6,9 and 12 respectively. Which one:

1. Forms an anion
2. Forms a cation

Name or state the following:

Elements having same mass number but different atomic number

Define the term of atomic number.

From the symbol \[\ce{^4_2He}\] for the element helium, write down the mass number and the atomic number of the element.

Elements X, Y, Z have atomic numbers 6, 9 and 12 respectively. Which one:

1. forms anion – negative ion;
2. forms cation – positive ion;
3. has 4 electrons in the outermost orbit. [Y, Z, X]

Elements A, B and C have atomic numbers 9, 20 and 10 respectively.

1. State which one is
   (1) a non-metal,
   (2) a metal,
   (3) chemically inert.[A,B,C]
2. Write down the formula of the compound formed by two of the above elements.[BA₂]

Cone H₂SO₄ acts as a ‘drying agent’ & a ‘dehydrating agent’. Explain and differentiate the words in italics.