Chemistry Class 9th

221- The energy released during the addition of 2nd electron is known as

A) 1st Electron affinity

B) 2nd electron affinity

C) ionization energy

222- O + e- →

a) O

B) O-

C) O-2

223-Following factors affect electron affinity

A) Atomic radius

B) Shielding effect

C) Both a and b

224-Atoms with smaller atomic radii have ------- electron affinity

A) Small

B) High

C) Constant

225-From top to bottom in a group electron affinity

A) Increases

B) Decreases

C) Remains same 

226- From left to right in a group electron affinity

A) Increases

B) Decreases

C) Remains same

227-The inner electrons shield the outer electrons from nuclear charge, this effect known a

A) Shielding effect

B) Screening effect

C) Both a and b

228-In a group shielding effect

A) Increases

B) Decreases

C) Remains same

229-In a period shielding effect

A) Increases

B) Decreases

C) Remains same

230-The ability of an atom to attract the shared pair of electrons towards itself is called

A) Electron affinity

B) Electro negativity

C) Ionization energy

231- Electronegativity --------- down a group

A) Increases

B) Decreases

C) Remains same

232-- Electronegativity --------- across a period.

A) Increases

B) Decreases

C) Remains same

233-The minimum amount of energy released during the addition of electron to the outermost shell of gaseous atom is called

A) Ionization energy

B) Electron affinity

C) Atomic radius

234- The highest electronegative element in periodic table is

A) Oxygen

B) Chlorine

C) Fluorine

235- The E.N. value of fluorine is

A) 4

B) 3

C) 2

236- The thing around us are composed of

A) Atom

B) Matter

C) Molecule

237- All matter is made of ____ units.

A) Thousands

B) Hundreds

C) Many

238- The sign of stability in valence shells.

A) 2 or 8

B) 3 or 5

C) 2 or 7

239- Attaining 2 electrons in valence is called ______.

A) Universal rule

B) Octet rule

C) Duplet rule

240- The ______ gases having 2 or 8 electrons.

A) Hydrogen

B) Halogen

C) Noble