Chemistry Class 9th

241- Attaining eight electrons valence shell is ________.

A) Duplet rule

B) Fix rule

C) Octet rule

242- Noble gases are ________

A) Reactive

B) Non-reactive

C) Stable

243- Atom combine one another called _______.

A) Chemical bonding

B) Polar bond

C) Non-Polar bond

244- by giving valence shell from other atom if they are less then ____.

A) Two

B) Three

C) Eight

245- hydrogen and helium which have only ___.

A) s-sub shell

B) p-sub shell

C) L-sub shell

246- If the bond formation is between ion, due to ______ force of attraction.

A) equal

B) electrostatic

C) both a and b

247- There are ________ type of covalent bonds.

A) one

B) four

C) two

248-When two approaching atom come closer the attractive as ________.

A) Repulsive

B) Impulse

C) Impulsive

249- The valence electron which are involved in ________.

A) Chemical bonding

B) Bonding electrons

C) Chemical combination

250- They are high electron affinities with _______ elements.

A) Electronegative

B) Electropositive

C) Both a and b

251- The type of chemical bond which is formed complete transfer of electron.

A) Ionic bond

B) Chemical bond

C) Covalent bond

252-Sodium being ______ element.

A) Electron positive

B) Electro negative

C) Both a and b

253- chlorine being _____ element.

A) electro positive

B) electro negative

C) both a and b

254- By losing one electron form outermost shell sodium becomes _____ ion.

A) Na+

B) Na-

C) Na±

255- By gaining one electron from outermost shell chlorine become.

A) Cl+

B) Cl-

C) Cl±

256- The types of covalent bond are ______.

A) four

B) two

C) one

257- Electronegativity --------- down a group.

A) Increases

B) decreases

C) remains same

258- The covalent bond is formed by ________.

A) mutual sharing

B) half sharing

C) both a and b

259- It is formed between ______ atom.

A) single

B) double

C) two

260- The electron that pair up to form a chemical bond

A) Bond pair

B) Lone pair

C) Dative covalent