The atom that would gain two electrons to fill its valence energy level is S(sulfur)
This is because s (sulfur) is in atomic number 16 with 2.8.6 of [Ne] 3s^2 2p^4 electronic configuration. This implies that sulfur has 6 valence electron and therefore it require two electron to fill its valence energy level and obtain 18 rule electrons.
There are 1.93 x 10²⁴ particles
<h3>Further explanation</h3>
Given
3.2 moles of Neon gas
Required
Number of particles
Solution
The mole is the number of particles(molecules, atoms, ions) contained in a substance
<em>1 mol = 6.02.10²³ particles
</em>
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
So the number of particles for 3.2 moles :
N = 3.2 x 6.02.10²³
N = 1.93 x 10²⁴
or
we can describe it using Avogadro's number conversion factor

LiF or lithium fluoride is the non covalent molecule or ionic compound.
Option 3.
<h3><u>Explanation:</u></h3>
Covalent molecules are those molecules which do have actual bonds between the atoms present in the molecule by sharing of the electrons. But in ionic molecules, there's no actual bonds between the atoms, but the oppositely charged ions are attracted towards each other by means of electrostatic force of attraction.
The molecules that are formed by the atoms with high electronegativity and electropositivity are actually ionic because the atoms with high electronegativity are able to actually gain electron readily and the atoms with high electropositivity are actually ready to give the electrons to the electronegative elements.
Lithium is highly electropositive and fluoride is highly electronegative. So they establish an ionic bond. But other molecules like fluorine molecule has both the electronegative elements, Carbon monoxide has carbon which isn't electropositive highly, and ammonia has hydrogen which isn't electropositive.
So lithium fluoride is the ionic compound.
The correct answer would be the last option. A double displacement type of reaction involves the switching of places the cations and anions accordingly. The given reaction is erroneous since in the product side the anions and cations are being paired which would not make sense. The correct reaction should be
4NaBr + Co(SO3)2 yields <span>CoBr4 + 2Na2SO3</span>