Abundance and Isotopes

Q. In the nitrogen family what is the order of electron affinity values with sign is it positive for all members of 15th group

Q.

Write the names of isotopes of hydrogen. What is the mass ratio of these isotopes?

Q.

Which of the following statements about Hydrogen is incorrect?

1. Hydrogen has three isotopes, of which, tritium is the most common

2. Hydrogen never acts as cation in ionic salts.

3. Hydronium ion, H₃O⁺ exists freely in solution.

4. Dihydrogen does not act as a reducing agent

Q.

Can you drink heavy water $\left({\mathrm{D}}_2\mathrm{O}\right)$?

Q.

Calculate electrons, protons and neutrons in $H_{3}P{O}_4$.

Q. The densities of graphite and diamond at 298 K are 2.25 and 3.31 g cm^-3 ​​​​​​, respectively. If the standard free energy difference (∆Gº) is equal to 1895 J mol–1, the pressure at which graphite will be transformed into diamond at 298 K is

A. 9.92 × 10⁵

B. 9.92 × 10<sup>8

C. 9.92 × 10^7</sup>

D. 9.92 × 10<sup>6

All options' unit is Pascal
----------------------------------------------------------------------------B-) :-D :-)
What should be the answer of this question according to you and why?
Please ex​plain in detail.</sup>

​​​​​​

Q.

Chlorine consists of $75\%$ Chlorine-$35$, $35\%$ and $25\%$of Chlorine-$37$. Calculate the average atomic mass.

Q.

Which of the following pairs are isotopes?

1. Ice and steam

2. Hydrogen and Deuterium

3. Nitric oxide and Nitrogen dioxide

4. Oxygen and Ozone

Q. The most abundant isotope of hydrogen is

1. Tritium
2. Deuterium
3. Protium
4. Para hydrogen

Q.

Which of the following statement is always correct?

1. An atom has an equal number of electrons and protons.

2. An atom has an equal number of electrons and neutrons.

3. An atom has an equal number of protons and neutrons.

4. An atom has an equal number of electrons, protons, and neutrons.

Q.

What is the charge of hydrogen?

Q.

Is hydrogen stable or unstable?

Q.

What is nascent hydrogen? why it is more reactive than ordinary hydrogen?

Q. Orthohydrogen and parahydrogen have

1. Same nuclear spin, different physical and chemical properties
2. Same nuclear spin with identical physical and chemical properties
3. Different nuclear spin with differences in physical and chemical properties
4. Different nuclear spin and with different physical properties

Q. Which of the following statement is not true about an atom..
1.atoms are not able to exist independently.
2.atoms are the basic units from which molecules and ions are formed.
3.atoms are always neutral in nature.

Q. Why is hydrogen fluoride more stable and has highest bond dissociation enthalpy then HCL HBR and HI.

Q.

What is planarity

Q.

Nuclear sizes are expressed in a unit named

Q. Determine the total number of neutrons in three isotopes of hydrogen.

Q.

The most abundant element in the earth is __

Q.

Name an atom which does not contain all three subatomic particles - proton, electron and neutron.

Q.

Question 5

Radioactive elements emit $\alpha ,\beta and\gamma$ rays and are chacterised by their half-lives. The radioactive isotope of hydrogen is

(a) protium (b) deuterium (c) tritium (d) hydronium

Q.

Calculate the number of unpaired electrons in the following gaseous ions: Mn³⁺, Cr³⁺, V³⁺ and Ti³⁺. Which one of these is the most stable in aqueous solution?

Q.

Which of the following isotopes make heavy water?

1. ${}_1{}^1\mathrm{H}$

2. ${}_1{}^2\mathrm{H}$

3. ${}_1{}^3\mathrm{H}$

4. both (b) and (c)

Q.

Write a short note on occurrence of hydrogen gas.

Q.

${\mathrm{D}}_2\mathrm{O}$ is known as ___.

Q.

Number of neutrons in Tritium are_______.

Q. Ordinary hydrogen at room temperature is a mixture of:

1. 75% orthohydrogen + 25% parahydrogen
2. 25% orthohydrogen + 75% parahydrogen
3. 50% orthohydrogen + 50% parahydrogen
4. 1% orthohydrogen + 99% parahydrogen

Q. Tritium, a radioactive element on decay forms an isotope of an inert gas and emits a beta particle. The inert gas is

1. Helium
2. Argon
3. Neon

Q. Which of the following is incorrect?

1. $\text{Hydrogen > Deuterium > Tritium}$
   (% relative abundance)
2. $\text{Hydrogen < Deuterium <Tritium}$
   (Boiling point)
3. $\text{Hydrogen < Deuterium <Tritium}$
   (Dissociation energy)
4. $\text{Hydrogen > Deuterium > Tritium}$
   (Melting point)