The correct option is B.
Mendeleev was the one who originated the idea of arranging elements in the periodic table according to their chemical and physical properties. He left spaces in the periodic table and predicted the discovery of those elements that had not been discovered then. One of these elements is Gallium. He predicted that gallium is going to be a metal and he gave the properties that the element will possess. He also predicted that the element gallium will be placed under aluminium in the periodic table.
Answer:
100ml of a stock 50% KNO3 solutions are needed to prepare 250ml of a 20% KNO3 solution.
Explanation:
In the given question it is mentioned that
S1=50%
V2=250ml
S2= 20%
We all know that
V1S1=V2S2
∴V1= V2×S2÷S1
∴V1= V2S2×1/S1
∴V1= 250×20÷50
∴V1= 100ml
<em>Let </em><em>the </em><em>mass </em><em>be </em><em>X </em><em>g</em>
<em>percentage </em><em>=</em><em> </em><em>X/</em><em> </em><em>6.</em><em>5</em><em>0</em><em> </em><em>*</em><em> </em><em>100 </em><em>=</em><em>2.</em><em>2</em><em>%</em>
<em>X=</em><em> </em><em>0.</em><em>1</em><em>4</em><em>3</em><em> </em><em>g</em>
<em>The </em><em>mass </em><em>is </em><em>0.</em><em>1</em><em>4</em><em>3</em><em> </em><em>g</em>
Covalent bonds and it is between the hydrogens (hydrogen bonds)
