## Which orbital of carbon can absorb photon but not emit it?

a) 1 s b) 2 s c) 3 p d) 2 p Answer: a Explanation: It is in the ...

## If wavelength of photon is 2.2×10^−11m, h=6.6×10^−34Js ,then momentum of photon is

If wavelength of photon is $2.2×10^{-11}m, h=6.6 ×10^{-34}Js$       , then momentum of photon is a) $3 × 10^{-23}Kg/s$

## The energy of a photon is given as △E╱atom=3.03∗10^−19 J atom^−1. Then the wavelength (λ) of the photon is.

The energy of a photon is given as $\triangle E\diagup atom = 3.03*10^{-19} J atom^{-1}$     . Then the wavelength ...

## Ratio of energy of photon of wavelength 3000 Å and 6000Å is

a) 3 : 1 b) 2 : 1 c) 1 : 2 d) 1 : 3 Answer: b Explanation: ...

## Chloride ion and potassium ion are isoelectronic. Then

a) their sizes are same b) chloride ion is bigger than potassium ion c) potassium ion is relatively bigger

## Which of the following is not iso electronic

a) $Na^{+}$ b) $Mg^{2+}$ c) $O^{2-}$ d) $Cl^{-}$ Answer: d Explanation: Na+ , Mg++, O2- contain 10 electrons each Cl- ...

## Among the following groupings which represents the collection of isoelectronic species?

a) $NO^{+},C_2^{2-},O_2^-,CO$ b) $N_{2},C_2^{2-},CO,NO$ c) $CO,NO^{+},CN^{-},C_2^{2-}$ d) $NO,CN^{-},N_{2},O_2^-$ Answer: c Explanation: The species $CO,NO^{+},CN^{-},C_2^{2-}$   Contain 14 electrons each.

## Which of the following isoelectronic species has the smallest atomic radius?

a) $N^{3-}$ b) $O^{2-}$ c) $F^{-}$ d) Ne Answer: c Explanation: $F^{-}$

## The hydride ion is isoelectronic with

a) $H^{+}$ b) $He^{+}$ c) He d) Be Answer: c Explanation: Hydride ion H- contains two electrons ...

## The number of electrons and neutrons of an element is 18 and 20 respectively. Its mass number is

a) 2 b) 17 c) 37 d) 38 Answer: d Explanation: For neutral atom . No. ...