Periodic table, Periodic properties and variations of Properties Assertion Reason Questions for ICSE Chemistry Class 10. This Assertion (A) Reason (R) type Questions is very helpful for this year students.
Question No. 1 and 2 consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
a) Both A and R are true, and R is the correct explanation of A.
b) Both A and R are true, and R is not the correct explanation of A.
c) A is true but R is false.
d) A is false but R is true
Que 1) Assertion: Group 1 elements are known as Alkali metals.
Reason: Hydrogen atom comes in group 1
Que 2) Assertion: Elements of group 18 are called as noble gases.
Reason: These elements have their outermost orbit complete.
Que 3) Assertion: There are seven horizontal rows.
Reason: There are 18 vertical groups.
Que 4) Assertion: Group 14 also known as carbon family.
Reason: Group 15 also known as boron family.
Que 5) Assertion: Elements of the period one have three shells.
Reason: Elements of the period two have two shells.
Que 6) Assertion:Mosley gives modern periodic table.
Reason: Niels Bohr gives extended form of periodic table.
Que 7) Assertion: Lanthanides also called as rare earths.
Reason: Actinides also called as radioactive elements.
Que 8) Assertion: Sodium has atomic number of 11
Reason: Florine has atomic number of 7
Que 9) Assertion: Electrons revolves around the nucleus in certain definite circular paths called orbit.
Reason: Electrons revolves in the orbit call shells.
Que 10) Assertion: If the number of electrons present in the outer most shell are 1,2,3, then their valency is 1,2,3, respectively.
Reason: Valency depend on the number of electrons in the outermost shell.
Que 11) Assertion: Atomic size increases top to bottom in periods.
Reason: There are increase in number of shells from top to bottom in period.
Que 12) Assertion: Valency is always positive.
Reason: Elements are classified according to their valancies.
Que13) Assertion:Cation is always larger than the parent atom.
Reason: Atomic size is the distance between centre of the nucleus and outermost shell.
Que 14) Assertion: Non metal usually have 5,6,7 in their outermost shell.
Reason: Metallic character depend on atomic size.
Que 15) Assertion:Metallic nature decreases across a period ,moving from left to right.
Reason: on moving across a period, nuclear pull increases due to the increase in atomic number.
Que 16) Assertion: Sodium ion is smaller than sodium atom.
Reason: Cation is formed by the loss of electron.
Que 17) Assertion: The tendency of losing electrons increases down the group.
Reason: The most reactive metal is at top of group 1.
Que 18) Assertion: The melting and boiling point of metal decreases on going down the group.
Reason:The melting and boiling point of non metalincreases on going down the group.
Que 19) Assertion: The atomic number represented by K.
Reason: The atomic mass number can be represented by A.
Que 20) Assertion: Anion is larger than the parent atom.
Reason: Anion is formed by the gain of electrons.
ANSWERS
1) B 6) D 11) A 16) A
2) A 7) B 12) C 17) C
3) B 8) C 13) D 18) B
4) C 9) C 14) C 19) D
5) D 10) A15) A 20) A