Mendeleev's Observations

Q. According to Mendeleev’s Periodic Law, the properties of elements are the periodic function of their ______.

1. Atomic density
2. Atomic volume
3. Atomic numbers
4. Atomic masses

Q.

When Mendeleev made the periodic table, the number of elements discovered till then were __.

Q. According to Mendleev's periodic law which properties of the elements are the periodic function of their atomic masses?

1. Chemical properties
2. Physical properties
3. Physical and chemical properties both
4. None of these

Q.

Which among the following formulae of elements was used by Mendeleev for giving the classification?

1. Carbonate

2. Nitrides

3. Oxides

4. Sulphides

Q. Noble gases were included in Mendeleev's periodic table in :

1. 1st group
2. 7th group
3. 8th group
4. none of the above

Q. Why did Mendeleev leave some gaps in his periodic table ?

Q.

Two elements X and Y need to be arranged in Mendeleev's periodic table. X has 3 protons more ​​​​​than Y but their neutrons are equal in number. Which of the following is correct about X and Y?

1. X will be placed after Y

2. Atomic mass of X is less than Y.

3. X and Y are isotopes

4. Y will be placed after X

Q.

Which chemical compounds of elements were used by Mendeleev to gauge their chemical similarities?

(A) Oxides (B) Chlorides (C) Hydrides (D) Sulphites

1. A, B, C

2. A, C

3. B, D

4. A, B, C, D

Q. According to Mendeleev's periodic law, the properties of elements are a periodic function of their:

1. Atomic volume
2. Atomic masses
   
3. Atomic number
4. Atomic size
   

Q. When Mendeleev started his work , the work , the number of known elements was:

1. 68
2. 53
3. 57
4. 63

Q.

When Mendeleev made the periodic table, the number of elements discovered till then were ___.

Q. Mendeleev arranged the known elements in a/an ______ order of their atomic masses.

1. increasing
2. decreasing
3. none of the above
4. random

Q.

Two elements X and Y need to be arranged in Mendeleev's periodic table. X has 3 protons more ​​​​​than Y but their neutrons are equal in number. Which of the following is correct about X and Y?

1. X and Y should be placed together.

2. Y will be placed after X.

3. X and Y are isotopes.

4. X will be placed after Y

Q.

Two elements X and Y need to be arranged in Mendeleev's periodic table. X has 3 protons more ​​​​​than Y but their neutrons are equal in number. Which of the following is correct about X and Y?

1. X will be placed after Y

2. X and Y should be placed together.

3. X and Y are isotopes.

4. Y will be placed after X.