Chemistry Class 9th

261-The sign of single covalent bond is _____.

A) –

B) +

C) =

262- In single covalent bond, one electron is contributed by _____ bonded atom.

A) Single

B) Double

C) Each

263- double covalent bond is indicated by ______.

A) –

B) +

C) =

264- In double covalent bond, each bonded atom contributes

A) Two bonded

B) Single bonded

C) Both a and b

265- Three lines are used to indicate covalent bond.

A) Single

B) Double

C) Triple 

266- The electronic configuration of valence shells is shown with small.

A) Dots

B) Crosses

C) Both a and b

267- Which scientist describe standard method of electronic configuration of valence shell of atom.

A) J. Charles

B) Robert Boyle’s

C) Lewis structure diagram

268- The bond pair of electron is donated by one bond atom only.

A) Ionic bond

B) Coordinate covalent bond

C) Polar covalent bond

269-- Electronegativity --------- across a period.

A) Increases

B) Decreases

C) Remains same

270- The atom which accept the electron pair.

A) Share

B) Lone pair

C) Acceptor

271- A small --------- is used to indicate the atom and pair of electron.

A) Arrow

B) Equal

C) Hyphen

272-The head of arrow is ______ the acceptor atom.

A) toward

B) beside

C) front

273- The non-bonded electron pair available on an.

A) Atom

B) Donor

C) Acceptor

274- The chemical formula of ammonium is.

A) NH3

B) NH4

C) HCl

275- The name of chemical formula of BF3 is.

A) Boron

B) Triflouride

C) Boron triflouride

276- In non-polar covalent bond it is formed b/w two.

A) Similar atom

B) Different atoms

C) Stable atom

277-In other non-polar bonds, this type of bond is called _____.

A) Pure covalent bond

B) Non-pure covalent bond

C) Metallic bond 

278- In polar covalent bond it is formed b/w two

A) Similar atom

B) Different atom

C) Sharing atoms

279. The atoms which attracts the bond pair more strongly than it is called as 2

A) More electronegative

B) More electropositive

C) Less electronegative

280-Polar covalent bond is formed when there will be ______ attraction.

A) Unequal

B) Equal

C) Strong