The charges for four ions are sodium (na) +1, calcium (ca) +2, fluorine (f) –1, and sulfur (s) –2. which would be an ionic bond that could form from any of these ions? naca2 na2s caf fs

Na₂S

Explanation:

Each of the atoms carry a charge with them, since sodium is in group 1 of the periodic table, it only needs to lose one electron in order to have a stable orbital. Hence when it loses a (negative) electron, the result is a positively charged ion (Na⁺). Similarly, when a group 7 atom such as fluorine obtains a stable orbital, it accepts an electron, since it is one short from its octet, and this creates a negatively charged ion (F⁻). The same thing can be said for atoms that gain or lose two electrons, and so forth.

A stable compound is created when ionic atoms form an overall neutral compound, such as NaCl. On its own, sodium in solution has a charge of +1, and chlorine has a charge of -1, so when combined, they cancel each other's charge, to produce a stable compound.

Taking the overall charges of the different compounds:

NaCa₂ = Na (+1) + 2Ca 2(+2) = (+1) + 2(+2) = +5 (unstable)

Na₂S = 2Na 2(+1) + S (-2) = 2(+1) + (-2) = 0 (stable)

CaF = Ca (+2) + F (-1) = (+2) + (-1) = +1 (unstable)

FS = F (-1) + S (-2) = (-1) + (-2) = -3 (unstable)

tube or goog with be a great resource to with that question

nec chapter 5 contains

c. information on special occupancy areas

nec chapter 6 covers

a. special equipment

which of the following rules contain the words shall or shall not and must be adhered to?

b. mandatory rules

which of the following rules identify actions that are allowed but not required and typically cover options or alternative methods?

c. optional rules

which of the following serves as the introduction to the nec and provides an overview of the book?

a. nec article 90

organizations that test products for safety are

c. nrtls

the nec is published by the

a national fire protection association

the nec is divided into

b. 9 chapters

the nec provides informative annexes for

c. informational materials and examples

two terms from nec article 100 that trainees should become familiar with are

b. labeled and listed

explanation: