Answer:
B. Electrical charges of polar covalent bonds
Explanation:
Lewis structures, also known as Lewis dot diagrams are diagrams that show the bonding between atoms of a molecule and lone pairs of an electron that may exist in the molecule.
Polar covalent bonds are bonds that occur where a pair of electrons is shared unevenly between two atoms
The Lewis notation as an agreed convection, uses the delta sign to indicate polar covalent bonds when they occur in compounds. It shows that the electrons are shared unevenly.
Consider the example attached below. The Lewis structure for HF is given. the δ+ is used to show the electropositive Hydrogen atom while the δ- is used to show the electronegative Fluorine atom in the bond.
<u>Answer:</u> The chemical reaction for the synthesis reaction is given below.
<u>Explanation:</u>
Synthesis reaction is defined as a chemical reaction in which two small chemical substances combine together to form a single compound. The general equation for this chemical reaction follows:

For the reaction of calcium and oxygen combining together to form calcium oxide, the equation follows:

By Stoichiometry,
2 moles of calcium element combines together with 1 mole of oxygen gas to produce 2 moles of calcium oxide.
Hence, the chemical equation for the reaction is given above.
A mole is mean the atomic number of 12 grams of carbon 12.
Divide both sides to get 104 and that’s your answer
Thermometer
Probably a digital thermocouple with high resolution