Identify each chemical reaction as endothermic or exothermic based on its description. Drag each tile to the correct location. Sodium bicarbonate reacts with citric acid. The temperature of the reaction mixture drops by 6.8°C. Zinc powder is stirred into a beaker containing copper(II) sulfate. The beaker feels warmer to the touch. Carbon in charcoal reacts with oxygen in the air. The reaction produces heat for cooking along with carbon dioxide. The chemical equation for hydrogen reacting with oxygen shows water and energy in the product. Cold packs are used to treat sports injuries. The temperature drop in the cold pack is activated by mixing ammonium nitrate with water. Salt water can treat a sore throat. Pouring salt into the water removes some of the energy from the water.

answer: option (b) is the correct answer.

explanation:

a covalent bond is formed by sharing of electrons. whereas polarity arises due to difference in electronegativity of two atoms.

therefore, more is the electronegativity of an atom which combines with the titanium, more readily it will induce a partial positive and negative charge.

thus, out of the given options fluorine is most electronegative and has an incomplete octet. therefore, it will readily combine with titanium to share the electrons and complete its octet.  

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.