Class 10 Science - Chapter Periodic Classification of Element NCERT Solutions | Element X forms a chloride with the form

(a)  What property do all elements in the same column of the Periodic Table as boron have in common?
(b)  What property do all elements in the same column of the Periodic Table as fluorine have in common?

The position of three elements A, B and C in the Periodic Table are shown below –

      Group 16          Group 17
            -                       -
            -                       A
            -                       -
            B                      C

(a) State whether A is a metal or non-metal.
(b) State whether C is more reactive or less reactive than A.
(c) Will C be larger or smaller in size than B?
(d) Which type of ion, cation or anion, will be formed by element A?

Compare and contrast the arrangement of elements in Mendeléev’s Periodic Table and the Modern Periodic Table.

How does the electronic configuration of an atom relate to its position in the Modern Periodic Table?

Which element has

(a) two shells, both of which are completely filled with electrons?
(b) the electronic configuration 2, 8, 2?
(c) a total of three shells, with four electrons in its valence shell?
(d) a total of two shells, with three electrons in its valence shell?
(e) twice as many electrons in its second shell as in its first shell?

How could the Modern Periodic Table remove various anomalies of Mendeléev’s Periodic Table?

Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.

In the Modern Periodic Table, which are the metals among the first ten elements?

Use Mendeléev’s Periodic Table to predict the formulae for the oxides of the following elements:

    K,     C,      AI,      Si,      Ba.

Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the Periodic Table. Write the electronic configuration of these two elements. Which of these will be more electronegative? Why?

What is a good source of energy?

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

What changes can you make in your habits to become more environment-friendly?

What is the difference between a reflex action and walking?

What is the importance of DNA copying in reproduction?

If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?

Why should a magnesium ribbon be cleared before burning in air?

Define the principal focus of a concave mirror.

You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?

What determines the rate at which energy is delivered by a current?

The kidneys in human beings are a part of the system for

   (a) nutrition.                  (c) excretion.
   (b) respiration.              (d) transportation.

How are the lungs designed in human beings to maximise the area for exchange of gases?

A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is (i) pushed into the coil, (ii) withdrawn from inside the coil, (iii) held stationary inside the coil?

What is a neutralisation reaction? Give two examples.

Judge the equivalent resistance when the following are connected in parallel – (a) 1 Ω and 10⁶ Ω, (b) 1 Ω and 10³ Ω, and 10⁶ Ω.

You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.

An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be –

(a) 100 W          (b) 75 W          (c) 50 W          (d) 25 W

State the rule to determine the direction of a (i) magnetic field produced around a straight conductor-carrying current, (ii) force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it, and (iii) current induced in a coil due to its rotation in a magnetic field.

What type of oxides are formed when non-metals combine with oxygen?