Question 5 : Metals are usually hard. Hence metals are strong and can withstand heavy loads over them. Due to this property, they are difficult to cut and can be used in the construction of heavy machines, building etc.<br/>On the other hand, non-metals are usually brittle. On hammering them they break into small pieces converting themselves into a fine powder.<br/><br/>In the following elements identify the elements that is relatively brittle?

Question 6 : Assertion: Alkali metals are strong reducing agents, while halogens [non-metals], are strong oxidising agents. Reason: Metals have 1,2 or 3 valence electrons so they always ionize by losing electrons while non metals have 4, 5, 6 or 7 valence electrons so they ionize by gaining electrons.

Question 9 : A mixture of minerals in the earth's crust from which it is profitable to extract a metal is called:

Question 10 : A strip of copper is placed in four different colourless salt solutions. Which one of the solutions will finally turn blue?<br/>

Question 11 : A non-metal $X$ exists in two different forms $Y$ and $Z$. $Y$ is the hardest&#160;natural substance whereas $Z$ is a good conductor of electricity. $Y$ is :<br/>

Question 12 : Assertion: No further heating is needed when sulphur reacts with metals. Reason: Reaction of sulphur with metals is exothermic.

Question 13 : ________ is called a space age metal and used in military jets and spacecrafts.

Question 17 : When copper is placed in the atmosphere for sufficient time a green crust is formed ion its surface the composition of green crust is&#160; ______________.

Question 20 : <span class="wysiwyg-font-size-small"><span class="wysiwyg-font-size-small"><p class="wysiwyg-text-align-left">The characteristic oxidation number of atoms in&#160;free metals is: &#160; &#160; &#160; &#160; &#160; &#160; &#160;&#160;</p>

Question 21 : A student added zinc granules to copper sulphate solution taken in a test tube. Out of the following, the correct observation (s) made by the student will be:<br/>

Question 22 : The metal which can replace copper from its salt solution is:

Question 23 : Which of the following mixtures is used in the preparation of tips of match sticks?

Question 24 : Which of the following non-metal is commonly used as pesticides and photography?

Question 26 : Which of the following is not used as cooking utensils even being a metal?

Question 28 : Sulphur reacts with hot aqueous potassium hydroxide, KOH to form :

Question 31 : In which of the following, use of non&#160;metals is more as compared to metals?

Question 34 : Determine which of the following match is correct:<br/><table class="wysiwyg-table"><tbody><tr><td></td><td>List I</td><td></td><td>List II</td></tr><tr><td>1</td><td>Phosphorus</td><td>a</td><td>fuel</td></tr><tr><td>2</td><td>Nitrogen</td><td>b</td><td>lights</td></tr><tr><td>3</td><td>Carbon</td><td>c</td><td>crackers</td></tr><tr><td>4</td><td>Oxygen</td><td>d</td><td>plant fertilizers</td></tr><tr><td>5</td><td>Neon</td><td>e</td><td>respiration</td></tr></tbody></table>

Question 37 : Paheli prepared a blue coloured solution of copper sulphate in beaker A and placed an iron nail in it. Boojho prepared a yellowish green solution of ferrous sulphate in beaker B and placed a copper wire in it. Changes they observe in the two beakers after an hour&#160;will be :<br/>

Question 38 : Which of the following non-metal can be used as plant fertilizer and for plant fixation?

Question 39 : Non-metals which are present in fertilizers and enhance the growth of plants is:<br/>

Question 45 : The most electropositive metals are isolated from their ores by ___________.

Question 47 : A metal $'M'$ reacts with nitrogen gas to give&#160;$'M_3N'$. $'M_3N'$ on heating at high temperature gives back $'M'$ and on reaction with water produces gas $'B'$. Gas $'B'$ reacts with aqueous solutions of $CuSO_4$ to form a deep blue compound. $'M'$ and $'B'$ respectively are:

Question 48 : When metallic copper comes in contact with moisture, a green powdery / pasty coating can be seen over it. This is chemically known as

Question 49 : $100\ g$ of a metal carbonate is heated which completely dissociated and forms $22.4\ L$ of $CO_{2}$ at STP. The metal carbonate is?

Question 50 : Hydrogen gas is not liberated when the following metal is added to dil. $HCl$