Need for Periodicity

Q. Calculate the number of atoms in 52 amu of Helium.

Q. State the main aim of classifying elements. Write the more fundamental property of elements that is used in the development of modern periodic table? Name and state the law based on this fundamental property. On which side of the periodic table one can find metals, non metals, Metalloids?

Q.

An element X has 7 electrons in its L shell. What is true about the element X?

I. It belongs to period 9 of modern periodic table.

II. Its atom contains 9 protons.

III. It has a valency of 7.

IV. Its atoms can accept an electron to acquire noble gas configuration.

1. (III) and (IV)

2. (I) and (II)

3. (II) and (Ill)

4. (Il) and (IV)

Q.

What name is assigned for elements from atomic number 89 to 103?

Q.

Which of the following is the correct order in terms of covalent radius?

1. 

2. 

3. None of these

4. 

Q. The properties of an element are determined largely by the electrons in its __________ shell.

1. outermost
2. penautimate
3. anti penultimate
4. None of the above

Q.

‘Valency is also the number of electrons -donated or accepted by an atom so as to achieve the stable electronic configuration of the nearest noble gas’.With reference to this definition.

b) State why the valency of-

(i) Sodium, Magnesium and Aluminum are +1, +2, and +3 respectively.

Q. When elements are placed in the order of their increasing atomic number,
the elements having the same number of __________ is repeated in such a way, so as to fall under the same group. Since, the electronic configuration of the valence shell electrons is same they show similar properties.

1. valence shell electrons
2. inner electrons
3. protons and neutrons
4. electrons present in inner shell

Q.

What do you understand by the periodicity of elements?

Q. An element belongs to group IA and 3rd period in the periodic table. Find an atomic number of that element. Find the atomic number of elements that are placed just
A) below

Q.

What is the fundamental difference between the electronic configuration of elements of group I A and group II A elements?

Q.

The periodical repetition of elements with similar properties after certain regular intervals when elements are arranged in order of increasing atomic number is called:

1. Periodicity
2. Valency
3. Regularity
4. None

Q.

(a) State the modern periodic law.

(b) How many periods and groups are there in the modern periodic table?

Q. The recurrence of similar properties of the elements when they are arranged in the order of increasing atomic number, after certain regular intervals, is called:

1. Group
2. Atomicity
3. Periodicity
4. None of above

Q.

__ are the atoms of different element with same mass number but different atomic number.

Q. When elements are placed in the order of their increasing atomic number, the elements having the same number of valence shell electrons is repeated in such a way, so as to fall under :

1. same group
2. different group
3. same period
4. different period

Q.

What is periodicity in elements?

Q. Members of the ______ have the similar electronic configuration of the valence shell and thus show the same valency.

1. different group
2. same group
3. same period
4. different period

Q. The incorrect statement among the following is:

1. among the isoelectric species, $N{a}^{+},M{g}^{2+}$ and $A{l}^{3+}$ ion having smallest radius is $A{l}^{3+}$ ion.
2. the properties of elements are periodic function of their atomic numbers.
3. the outermost electronic configuration of group $15$ elements is $n{s}^{2}n{p}^5$.
4. electronegativity of an element depend upon its atomic size.

Q. According to Moseley's periodic law the physical and chemical properties of elements are the periodic function of their atomic .

1. structures
2. masses
3. numbers

Q.

Consider five elements:- V, W, X, Y and Z having atomic number 10, 20, 30, 40 and 50, respectively.

Which of these is/are non-metals?

1. ‘V’ and ‘Y’

2. ‘Y’ only

3. ‘V’ only

4. ‘Y’ and ‘Z’

Q.

Which of the following electrons have little influence on the properties of elements?

1. outer electrons
2. electrons have no influence on properties of elements
3. inner electrons
4. Both A and C

Q. Which of the following electrons have much influence on the properties of elements?

1. Valence electrons
2. None of the above
3. Electrons in penultimate shell
4. Electrons in anti penultimate shell

Q. Identify the five essential elements to life as suggested in the Vedas.

1. Water
2. Plants
3. Animals
4. Fire
5. Earth
6. Aether
7. Air
8. Wood

Q. In a shop, all soaps are kept together at one place while biscuits are kept together elsewhere. Even among soaps, bathing soaps are stacked separately from washing soaps. Such kind of arrangement is technically called as ‘classification’. Similarly, scientists brought order from chaos with an orderly arrangement of elements. Such arrangement of chemical elements is named as:

1. Chemistry Table
2. Classified Table
3. Chemical Table
4. Periodic Table

Q. The properties which repeats repeatedly at a regular interval is called___________.

1. Anomalous properties
2. Periodic properties
3. Diagonal properties
4. None

Q.

What is the correct sequence

1. Newland's law of octaves

2. Law of triads.

3. Modern periodic table.

4. Mendeleev's periodic table.

1. 3-2-1-4

2. 2-1-4-3

3. 1-2-3-4

4. 3-2-4-1

Q. A graph is obtained on plotting the square root of the frequencies of the characteristic X-rays of elements against their atomic numbers.

1. parabola
2. hyperbola
3. straight line