Based on their locations in the periodic table, which two elements are most likely to form covalent bonds with each other?

magnesium (Mg) and sulfur (S)

sodium (Na) and bromine (Br)

potassium (K) and iodine (I)

nitrogen (N) and oxygen (O)

Nitrogen (N) and Oxygen (O)

Explanation:

Nitrogen (N) has five valence electrons, so it needs three more valence electrons to complete its octet. Two nitrogen atoms will combine. Each will share three electrons to form three covalent bonds, i.e., a triple bond, resulting in a nitrogen molecule.

The valency of oxygen (O) is two, which means that it requires two electrons to complete its outermost (valence) shell. Therefore, two oxygen atoms will combine and share their two valence electrons, resulting in a double bond.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.

what is the average time it took the car to travel 0.25 meters?

⇒ 2.23 seconds

what is the average time it took the car to travel 0.50 meters?

⇒ 3.13 seconds