... Free Radicals are molecules or ions that have an unpaired electron. They tend to be very reactive and are thought to contribute to the aging process. A "dimer" forms when two of the same molecules combine (dimerize). Draw a Lewis structure for each of the substances below and indicate which are free radicals. For a free radical the unpaired electron goes on the least electronegative element, which is usually the central atom. Key: ... y = Yes ... n = No 1. BrO2 2. OCl2 3. ClO2 4. NO2- Submit AnswerRetry Entire Group

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).