Newland's Law of Octaves : Assumptions and Limitations

Q.

Among $\mathrm{O},\mathrm{C},\mathrm{F},\mathrm{Cl},\mathrm{Br}$ the correct order for increasing radii is

1. $\mathrm{F},\mathrm{O},\mathrm{C},\mathrm{Cl},\mathrm{Br}$

2. $\mathrm{F},\mathrm{C},\mathrm{O},\mathrm{Cl},\mathrm{Br}$

3. $\mathrm{F},\mathrm{Cl},\mathrm{Br},\mathrm{O},\mathrm{C}$

4. $\mathrm{C},\mathrm{O},\mathrm{F},\mathrm{Cl},\mathrm{Br}$

Q.

X and Y are the two elements having similar properties which obey Newland’s law of octaves. How many elements are there in-between X and Y?

Q. Which amongst the following elements has the largest atomic size?

1. Beryllium
2. Carbon
3. Oxygen
4. Fluorine

Q.

Arrange the elements Li, Na, K, Rb as required

Increasing order of atomic radii

Q.

Look at the atomic radii of some elements of second period and answer the questions:

Element	B	Be	O	N	Li	C
Atomic radii in pm	88	111	66	74	152	77

Arrange these elements in the decreasing order of their atomic radii.

Q.

Based on Newlands’ law of octaves, identify the set of elements that possess similar properties.

1. Li, Na
2. Be, Mg
3. B, Al
4. C, Al

Q.

Which periods are called short periods and which periods are called long periods? Why?

Q.

Briefly explain the first classification of elements and Mendeleevs periodic table.

Q.

The long form of periodic table consists of -

1. seven periods & eight groups

2. seven periods & eighteen groups

3. eight periods & eighteen groups

4. eighteen periods & eight groups

Q.

The alkali metal in the second period.

Q.

Which of the following pair of an atomic numbers represents s-block elements?

1. $7,15$

2. $6,12$

3. $9,17$

4. $3,20$

Q.

Which pair of elements of the following sets is likely to have similar chemical behavior?

1. Sodium and aluminium

2. Argon and potassium

3. Boron and germanium

4. Nitrogen and phosphorous

Q.

The Newland’s law of octaves for the classification of elements was found to be applicable only up to the element :

(a) potassium (b) calcium (c) cobalt (d) phosphorus

Q. Atomic number is considered to be a more appropriate parameter than atomic mass for classification of elements in a periodic table. why? (5 marks)

Q.

Give one similarity between Dobereiners triads and Newlands law of octaves.

Q.

The atomic radius increases on moving down a group from top to bottom

1. True
2. False

Q.

The correct order of increasing acidic nature of SO₂, SIO₂, P₂O₃ and Al₂O₃ is-

1. SO₂ < P₂O₃ < SiO₂ < Al₂O₃

2. Al₂O₃ < SiO₂ < SO₂ < P₂O₃

3. Al₂O₃ < SiO₂ < P₂O₃ < SO₂

4. SiO₂ < SO₂ < Al₂O₃ < P₂O₃

Q.

The non-metallic element present in the third period other than Sulphur and Oxygen.

Q.

The size of the molecules is of the order of ____________.

1. 10^-8 to 10^-12 m

2. 10^-6 to 10^-8 m

3. 10^-8 to 10^-15 m

4. 10^-8 to 10^-10 m

Q. Newland's law of octaves can be applied to the set of elements consisting of .

1. Na, Li, K
2. H, Si, Al
3. Be, Mg, Ca

Q.

The three elements X, Y and Z in a group have ionic radii $1.33{\rm A},0.95Aand0.60A$, respectively. Arrange them in increasing order of atomic numbers.

Q. Name two metals which are found in nature in the free state.

Q.

An alkali earth metal in the third period.

Q.

According to Newlands law of octaves 3rd element will resemble in its properties to -

1. ninth element

2. eighth element

3. tenth element

4. eleventh element

Q.

Group IIA elements are known as-

1. Alkali metals

2. Alkaline earth metals

3. Halogens

4. Noble gases

Q.

Among the elements Li, K, Ca, Sr and Kr which one has the lowest atomic radius and which one has the highest?

Q.

Isodiaphers are atoms having-

1. p/n constant

2. (p+n) constant

3. (n-p) constant

4. (n-p) different

Q.

The ionization energy of elements in a period increases going from left to right.

1. True
2. False

Q. According to the Newlands' law of octaves, the properties of fluorine are similar to those of ________ .

1. hydrogen
2. lithium
3. sodium
4. potassium

Q.

Newlands gave the law of octaves. Following questions are based on this law.
(i) How many elements were known at the time of Newland?
(ii) If one considered nitrogen as the first member of Newlands octaves, then which element is present at the eighth position from it?
(iii) "Newland adjusted two dissimilar elements under the same slot". Comment on this statement.