<u>Halogens are reactive because:</u>
They have high electronegativity and also high nuclear charge. So, they are reactive and also gain an electron when they react with other elements.
Since they are very reactive, halogens are very harmful to living organisms. Some of the halogens are fluorine, chlorine, bromine, iodine, astatine. These are mostly non metals. Fluorine is one of the most reactive gas and also very toxic gas. When Fluorine reacts with glass along with small amounts of water, it forms silicon tetra fluoride (SiF4). Hence fluorine should be handled with substances like the inert organofluorine compound Teflon.
The only answer we can choose
<span>B.
energy needed to break chemical bonds.</span>
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<span>This is a physical property. Physical properties involve changes of phase, or state of matter, of which melting is an example. Melting involves a change from a solid state to a liquid state. The internal energy of the solid increases, usually by applying heat, which increases the temperature to the melting point of the substance.</span>
<span>A.The amount of time it takes for half of the material to decay</span>