Author name: Elite Tutors

1. GroupAns: The eighteen vertical columns in the modem periodic table are called as groups. 2. PeriodAns: The seven horizontal rows in the modem periodic table are called as periods. 3. Atomic radiusAns: For an isolated atom, the distance between the centre of the nucleus of the atom and the outermost shell is called its

1. If the distance between two masses is doubled, the gravitational force between them becomes less than the previous force.Ans: Right 2. The CGS unit of G is dyne.cm2/g2.Ans: Right 3. The value of gravitational acceleration at the centre of earth is zero. Ans: Right 4. The value of g is highest at the equator.Ans:

1. The atom having the biggest atomic size from period 2.Ans: Lithium (Li) 2. The atom having the smallest atomic radius from zero group.Ans: Helium (He) 3. The family of group 1 elements.Ans: Alkali metals 4. Highest reactive nonmetal.Ans: Fluorine (F) 5. The element having stable electron configuration from the third period.Ans: Argon (Ar) 6.

1. According to Newland’s octave rule, chlorine shows similarity with fluorine. Because, chlorine is …………………Ans: According to Newland’s octave rule, chlorine shows similarity with fluorine. Because, chlorine is the eighth element from fluorine. 2. According to Mendeleev’s periodic law properties of elements are ……………….Ans: According to Mendeleev’s periodic law properties of elements are a periodic

1. Element A and B follows the Newland’s octaves rule. How many elements are there in between A and B?Ans: Element A and B follows the Newland’s octaves rule and six elements are there in between A and B. 2. Write the characteristic of Dobereiner’s triads?Ans: In each triad, the elements were placed according to

1. F, K, Cl, IAns: KK is placed in group 1 while others are placed in group 17 of the modem periodic table. 2. Lithium, Sodium, Magnesium, PotassiumAns: MagnesiumMagnesium is an alkaline earth metal while others are alkali metals. 3. Beryllium, Helium, Neon, ArgonAns: BerylliumBeryllium is an alkaline earth metal while others are noble gases.

1. Eka boron : Scandium :: Eka Aluminum : _________Ans: Eka boron : Scandium :: Eka Aluminum : Gallium 2. Mendeleev’s periodic table : atomic mass :: Modem periodic table : _________Ans: Mendeleev’s periodic table : Atomic mass :: Modem periodic table : Atomic number 3. Group 1 and 2 : s block :: group

1. A …………… is necessary to change the speed as well as the direction of motion of an object. (A) force            (B) inertia              (C) momentum         (D) motion 2. The orbit of a planet revolving around a star is ………….. (A) circular