Answer:
SiF4 is not a polar covalent bond.
Explanation:
SiF4 is a nonpolar molecule because the fluorine's are arranged around the central silicon atom in a tetrahedral molecule with all of the regions of negative charge cancelling each other out.
Isotopes of elements where the nucleas is unstable generally release nuclear radiation. So unstable atoms
These are main components of Industrial Smog. Smog is air pollutant. Main sources of Smog are 1) Coal, 2) Transportation Emission, 3) Natural Causes. Those areas are mainly effected which are located in Industrial Zones and those which has high traffic density. Cities like Delhi, Beijing, London, Maxico City, Log Angeles, Tehran e.t.c are reported to be highly effected by smog. Among these polutants, CO₂ is the main source of Global Warming, CO has adverse effects on human health as it has 200 times more potency to bind with Hemoglobin compared to Oxygen, SO₂ when present in air reacts with water producing acid rain e.t.c.