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.
The energy released from 1 gram of uranium is more than 1 million times greater than the energy released from 3 grams of coal is True.
<u>Explanation:</u>
Nuclear Fission is the process in which splitting of a nucleus takes place that releases free neutrons and lighter nuclei. The fission of heavy elements like "Uranium is highly exothermic" and releases "200 million eV" compared to the energy that is released by burning coal which gives a few eV.
In the given example, it is obvious that the energy released from 1 gram of uranium is more than that of the energy released from 3 grams of coal because the amount of energy released during nuclear fission is millions of times more efficient per mass than that of coal considering only 
part of the original nuclei is converted to energy.
Malleability is the property due to which substances tend to hammered into thin sheets when pressure is applied. Malleability is observed in metal as the metal atoms are bound by metallic bonds. The layers of metal atoms can roll over each other without breaking the metal bond when pressure is applied. In the periodic table malleability decreases as the metallic nature decreases. Among the given metals Al is the most metallic element, followed by Zinc an Carbon is a non metal. Therefore, the order of increasing malleability will be C, Zn, Al
Solids - particles are very close together (highest density on the list)
Liquids - the particles slide past one another
Gases - particles bounce off of surroundings and the same particles of the gas
