Burning methane in air is an exothermic reaction

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The burning of methane in the presence of air is an exothermic reaction. The given statement is true.

Exothermic Reaction:

The chemical reaction in which heat energy is released during the reaction.

For example-  the burning of 1 mole of methane in the air releases 810 kJ of heat energy.

Therefore, the burning of methane in the presence of air is an exothermic reaction.

To know more about Exothermic Reactions:

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Hydrocarbon fuels like methane (CH4) burn in the presence of oxygen to produce carbon dioxide and water. This process of combustion releases energy. When energy is released during the course of a chemical reaction, it is said to be an EXOTHERMIC reaction. The combustion of of methane gas releases 50.1 kJ/g.

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- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms

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