Question Text
Question 3 :
_________ is the smallest unit of matter which may or may not have an independent existence, but always takes part in a chemical reaction.
Question 6 :
The symbolic representation of elements in a chemical compound is known as:
Question 9 :
_____ are the basic units of matter and the defining structure of elements.
Question 11 :
The ratio of radius of the nucleus to the radius of the atom is of the order:
Question 13 :
Which of the following reactions is not according to the law of conservation of mass?
Question 17 : <p><span>16.8 g of metal carbonate on thermal decomposition gave 8 g of metallic oxide and 8.8 g of carbon dioxide. They follow:</span></p>
Question 18 : <p><span>A sealed tube containing phosphorus was weighed and heated carefully. After completion of the reaction, the tube was re-weighed under similar conditions. The weight of the tube will:</span></p>
Question 19 :
A metal sulphate has the formula MSO$_4$. A chloride of the same metal will have the formula__________.
Question 21 :
Which of the following statements is correct about the reaction given below?<span><br>$\displaystyle 4Fe\left ( s \right )+3O_{2}\left ( g \right )\rightarrow 2Fe_{2}O_{3}\left ( g \right )$<br></span>
Question 22 : Which of the following is a suitable example for illustrating the law of conservation of mass?<div> (Atomic mass of O = 16 g/mol, H = 1 g/mole)<br/></div>
Question 23 :
Which of the following contains the greatest number of atoms ?
Question 24 :
The number of gold atoms in 300 mg of a gold ring of 20-carat gold ($Au = 197$: pure gold is 24 carat) is:
Question 25 :
<br/>The ratio of unpaired electrons present in d orbitals of $Co^{2+}$ and $Cr^{3+}$<span class="MathJax"><span class="MJX_Assistive_MathML">Co2+</span></span> is ____.
