Answer:
The correct option here is the first option
Explanation:
Covalent bond is the bond that involves the sharing of electrons between the participating atoms. The electrons (in the outermost shells of the atoms) that are involved this sharing are called the "shared pair" while those electrons (in the outermost shells of the atoms) that are not involved in this sharing are called the "lone pair". Bonding eventually leads to each of the participating atoms achieving it's octet configuration.
Carbon will bind covalently with fluorine (to form carbon tetrafluoride) with each of the electrons on the outermost shell of the carbon been shared covalently with fluorine atoms (that also requires just one electron to achieve it's octet configuration). Thus, at the end, we would have one carbon atom being covalently linked to four flourine atoms.
Answer:

Explanation:
Hello!
In this case, when solid calcium carbonate, CaCO3 (s), is decomposed by the action of thermal energy (heat), solid calcium oxide, CaO (s) and carbon dioxide gas, CO2 (g) are yielded via the following reaction:

However, since calcium carbonate is solid as well as calcium oxide and carbon dioxide is given off as a gas, we write:

Which also balanced.
Best regards!
Explanation:
Iron, like other metals, conducts heat and electricity, has a luster, and forms positive ions in its chemical reactions. Pure iron is fairly soft and can easily be shaped and formed when hot. Its color is silvery white. Iron is easily magnetized.
Due to its higher oxygen content and based on its structure dietheylene glycol has a higher energy efficiency (cal/g) compared to isopropanol and paraffin wax.
<h3>What is the calorific value of a fuel?</h3>
The calorific value of a fuel is the amount of heat energy released from the combustion of the fuel under standard conditions.
Dietheylene glycol, isopropanol and paraffin wax are all used as fuels.
However, due to it higher oxygen content and based on its structure, diethethylene glycol has a higher calorific value than either isopropanol or paraffin wax.
Therefore, dietheylene glycol has a higher energy efficiency (cal/g) compared to isopropanol and paraffin wax.
Learn more about calorific value at: brainly.com/question/12975147
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