Need for Classification

Q. The mass number of calcium which has 20 protons and 20 neutrons is .

1. 60
2. 20
3. 40

Q.

What are the characteristics of Mendeleevs periodic table?

Q. The atomic weight of carbon is .

1. 12u
2. 30u
3. 18u
4. 6u

Q.

The name of copper and its symbol comes from the Greek name Cuprum.

1. True
2. False

Q.

Give the values for the following,

Gram atom of Potassium = ____ g of Potassium?

Q.

What is the common name for VII A group elements?

Q. The vertical columns in the Mendeleev’s periodic table are called ______.

1. periods
2. triads
3. groups
4. octaves

Q.

Discuss briefly the modern periodic table

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. 2-1-4-3

2. 1-2-3-4

3. 3-2-1-4

4. 3-2-4-1

Q. is a noble gas among the following.

1. Hydrogen
2. Calcium
3. Boron
4. Helium

Q.

$X$ and $Y$ are two elements having similar properties which obey Newlands law of octaves. Write the number of elements between $X$ and $Y$?

Q. Metallic character _________ down the group in the periodic table.

1. increases
2. decreases
3. increases and then decreases
4. decreases and then increases

Q.

Triads of elements arranged in increasing order of their atomic masses were proposed by-

1. Lothar Meyer

2. Dobereiner

3. Dmitri Mendeleev

4. Ernest Rutherford

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. Chemical Table
3. Periodic Table
4. Classified Table

Q.

How many groups and periods are there in the Mendeleev's periodic table?

1. There are eight groups and seven periods.

2. There are seven groups and seven periods.

3. There are six groups and seven periods.

4. There are eight groups and six periods.

Q.

Given below are the elements with their atomic masses. Identify a set of elements which is not a Dobereiner's triad.

1. Lithium (7), sodium (23), potassium (39)

2. Nitrogen (14), phosphorus (31.0), arsenic (75)

3. Calcium (40), strontium (88), barium (137)

4. Chlorine (35.5), bromine (80), iodine (127)

Q.

Answer the following questions regarding the modern version of Mendeleevs periodic table.

Into how many periods is the periodic table divided?

Q. The modern periodic table is made up of 118 chemical elements.

1. False
2. True

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. 2-1-4-3

2. 1-2-3-4

3. 3-2-1-4

4. 3-2-4-1

Q. The term 'noble' in noble gases means chemically stable and unreactive.

1. False
2. True

Q. Assertion (A) : In Newlands’ octaves, the properties of lithium and sodium were found to be same.​
Reason (R) : Sodium is the eight element after lithium in Newland’s octave.

1. (A) is true, but (R) is false.
2. Both (A) and (R) are true, but (R) is not the correct explanation of the (A).
3. Both (A) and (R) are true, and (R) is correct explanation of the (A).
4. (A) is false, but (R) is true.