2020 · Q9
Which one of the following statements about alkaline earth metals is not true?
general-sciencechemistry
- AStrontium salts burn with a red flame
- BBarium metal is used in medicine to examine the alimentary canal of a patient by X-ray
- CGreen plants need magnesium in order to make the chlorophyll that trap the energy from sunlight in photosynthesis
- DRed color of gemstone Ruby is due to the element beryllium present in it
Explanation
Strontium salts burn with a crimson-red flame (A true); barium sulfate, as a 'barium meal', is swallowed to image the alimentary canal by X-ray (B true); and magnesium sits at the centre of the chlorophyll molecule that traps sunlight for photosynthesis (C true). But the red colour of ruby comes from chromium impurities in corundum (aluminium oxide), not from beryllium — so D is the statement that is not true.