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Which of the following statements is false ?. When burned in air at 1 atm pressure, Li forms a normal oxide. When burned in air at 1 atm pressure, the IA metals (other than Li) form peroxides or superoxides. The IA metal oxides are basic.
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Which of the following statements is false? • When burned in air at 1 atm pressure, Li forms a normal oxide. • When burned in air at 1 atm pressure, the IA metals (other than Li) form peroxides or superoxides. • The IA metal oxides are basic. • The IA metal oxides react with water to form weak bases. • The IA metals react vigorously with water.
Which one of the following compounds or elements is not correctly matched with a use? Substance / Use • NaHCO3 / baking soda • NaOH / production of soap • K2CO3 / treatment for manic depression • KNO3 / a fertilizer • Li / heat transfer in experimental nuclear reactors
Which one of the following compounds is not correctly matched with its common name? Compound / Common Name • NaHCO3 / baking soda • Na2CO3·10H2O / washing soda • KNO3 / niter or saltpeter • NaNO3 / caustic soda • Na2CO3 / soda or soda ash
Which one of the following metals exhibits the photoelectric effect with the lowest energy radiation, thereby making it useful in photoelectric cells? • Li • K • Cs • Be • Ba
Which of the following element(s) is not known to be essential to humans? • Mn • Se • Zn • Sn • Cr
Which one of the following is required for thyroid hormones function? • Hg • Br • Zn • Co • I
Which one of the Group IIA metals reacts with oxygen, O2, almost exclusively according to the equation give below? M + O2 {image} MO2 • Be • Mg • Ca • Sr • Ba
Which one of the following compounds or elements and its uses do not match? Substance / Use • 2MgSO4·H2O / plaster of Paris • strontium salts / red color in fireworks • BaSO4 / absorbs x-rays • Be / windows for x-ray tubes • Mg / photographic flash bulbs
Which one of the following is not a post-transition metal? • aluminium • cesium • bismuth • lead • gallium
Which one of the following ions hydrolyzes the most extensively? • K+ • Ca2+ • Mg2+ • Al3+ • Tl3+
Which one of the following has the highest melting point? • Sc • Ti • Cr • Cu • Zn
Which one of the following is the strongest oxidizing agent? • Cr(OH)2 • CrCl3 • K CrO2 • K2Cr2O7 • Cr2O3