Atomic Radius

Q. The radius (r) of the nucleus of an atom is related to { its mass number (A) as r=R_0A^\ast . The value of x is

Q.

Tendency of an atom in a molecule to attract the shared pair of electron towards itself is called:

1. Ionisation enthalpy

2. Periodicity

3. Electronegativity

4. Electron gain enthalpy

Q. The dipole moment of $KCl$ is $3.336\times {10}^{-29}Coulombmeters$ which indicates that it is a highly polar molecule. The interionic distance between $K^{+}$ and $C{l}^{-}$ in this molecule is $2.6\times {10}^{-10}m$. The percentage ionic character of $KCl$ molecule, if there were opposite charges of one fundamental unit located at each nucleus is:

1. $70.8\%$
2. $19.8\%$
3. $80.2\%$
4. $30.2\%$

Q. which of the elements has the strongest tendency to form electrovalent compond? 1. Li 2. Na 3. Be 4. M

Q. We say that due to repulsive force present in real gases, volume occupied by the molecule is more than ideal gas that is, correction factor is given by (V-nb)but if we consider attractive force b/w the molecules it should actually pull the molecules and decrease its volume right but we dont consider attractive forces at all, why??

Q. The correct order of increasing ionic radius for $F^{-},N{a}^{+},S^{2-},C{l}^{-}$ and $K^{+}$ is:

1. $F^{-}<N{a}^{+}<S^{2-}\approx C{l}^{-}<K^{+}$
2. $N{a}^{+}<K^{+}<F^{-}<C{l}^{-}\approx S^{2-}$
3. $N{a}^{+}<F^{-}\approx K^{+}<C{l}^{-}<S^{2-}$
4. $N{a}^{+}\approx F^{-}<C{l}^{-}<S^{2-}<K^{+}$

Q. 16.The rms speed of helium in ms-1 (atomic mass =4.0g mol-1 )at 400k is

Q. How many protons, electrons and neutrons are presents in 2.4g of {}_{16}^{32}S ?

Q.

Hydrides are classified as:

1. Non-covalent, non-molecular and stoichiometric

2. Non-molecular, non-metallic and stoichiometric

3. Non-ionic, non-covalent and non-metallic

4. Ionic, covalent and metallic

Q. Match the elements of given atomic number with their properties.

	Column $I$		Column $II$
$P$	$11$	$1$	IE is maximum among the given elements
$Q$	$19$	$2$	Alkali metal
$R$	$37$	$3$	Largest size among the given elements
$S$	$55$	$4$	Position next to $Kr$

1. $P-1:Q-1,2:R-1,2:S-3,4$
2. $P-2,3:Q-1,2:R-2,4:S-2,3$
3. $P-1,2:Q-2,4:R-2,4:S-2,3$
4. $P-1,2:Q-2,:R-2,4:S-2,3$

Q. Among the following compounds, which has the maximum lattice energy?

1. $KBr$
2. $NaCl$
3. $NaF$
4. $LiF$

Q. Which property of the alkali metals is listed properly?

1. Radioactive element - Li

2. Strongest Reducing agent - Na
3. Highest Electropositive element - Cs
4. Lowest density - K

Q. 34. what is effective nuclear charge? is there any formula for it?

Q. Find out ratio of enrgy of second excited state of hydrogen to third excited state of helium.

Q. Q). Which of the following substances has the highest melting point ?
(1) NaCl
(2) KCl
(3) MgO
(4) BaO

Q. Which of the following is the correct order of the atomic size of C, N, P and S?

1. $\text{N < C < S < P}$
2. $\text{N < C < P < S}$
3. $\text{C < N < S < P}$
4. $\text{C < N < P < S}$

Q.

when the pressure approaches zero why do the real gases behave like ideal gases?

Q.

Which of the following statements is true?

1. The atomic radius of Ga is more than Al.

2. The atomic radius of Ga is equal to Al.

3. The atomic radius of Ga is less than Al.

4. The atomic radius of Ga is less than B.

Q.

Describe the theory associated with the radius of an atom as it

(a) gains an electron

(b) loses an electron

Q. The radius of a divalent cation $A^{2+}$ is $94pm$ and that of a divalent anion $B^{2-}$ is $146pm$. The compound $AB$ has:

1. Caesium chloride like structure
2. Antifluorite structure
3. Zinc blende structure
4. Rock salt structure

Q.

Which of the following has the maximum atomic radius?

1. Al

2. Si

3. P

4. Mg

Q. The correct decreasing order of atomic size of the following species is:
$K^{+},C{l}^{-},S^{2-},C{a}^{2+}$

1. $C{a}^{2+}>K^{+}>C{l}^{-}>S^{2-}$
2. $K^{+}>C{a}^{2+}>C{l}^{-}>S^{2-}$
3. $S^{2-}>C{l}^{-}>K^{+}>C{a}^{2+}$
4. $S^{2-}>C{l}^{-}>C{a}^{2+}>K^{+}$

Q. Why hydrogen was not involved in Newlands law of octaves? Is hydrogen an inert gas?

Q. 9.Deuterium is mostly found as HD. What is meant by HD ?

Q. moles of kclo_{3 required forproducing sufficient o_{2 to }} react with 0.1 mole of aluminium

Q. The atomic radii of fluorine and neon in Angstrom units are respectively given by

1. $1.60,1.60$
2. $0.72,0.72$
3. $0.72,1.60$
4. None of the above

Q. The value of lattice energy is affected by

1. Mass of ions
2. Charge of ions only
3. Size and charge of ions
4. Size of ions only

Q. 62 Difference b/w rhombic and monoclonic sulfur

Q. We say that due to repulsive force present in real gases, volume occupied by the molecule is more than ideal gas that is, correction factor is given by (V-nb)but if we consider attractive force b/w the molecules it should actually pull the molecules and decrease its volume right but we dont consider attractive forces at all, why??

Q.

give reasons:

(1) AlCl3 is a poor conductor of electricity in molten state.

(2) AlF3 is a high melting solid whereas SiF4 is a gas.