Answer: Option (d) is the correct answer.
Explanation:
An orbital is defined as the energy shell which can contain a maximum of two electrons with opposite spins.
A wave like behavior of an electron is determined by an orbital and basically an orbital acts like a mathematical function.
For example, in a p-sub shell the orbitals present are
,
and
.
Therefore, we can conclude that orbitals are defined by energy level.

Actually Welcome to the Concept of the Ionic bonds.
Since Sodium (Na) is a cation and Chlorine (Cl) is a Anion, they both form a Ionic bond called as NaCl (common salt)
So answer is, Na and Cl
Answer: 0.4M
Explanation:
Given that,
Amount of moles of NaOH (n) = ?
Mass of NaOH in grams = 40.0g
For molar mass of NaOH, use the atomic masses: Na = 23g; O = 16g; H = 1g
NaOH = (23g + 16g + 1g)
= 40g/mol
Since, n = mass in grams / molar mass
n = 40.0g / 40.0g/mol
n = 1 mole
Volume of NaOH solution (v) = 2.5 L
Concentration of NaOH solution (c) = ?
Since concentration (c) is obtained by dividing the amount of solute dissolved by the volume of solvent, hence
c = n / v
c = 1 mole / 2.5 L
c = 0.4 mol/L (Concentration in mol/L is the same as Molarity, M)
Thus, the concentration of a solution of a 40.0 g of NaOH in 2.5 L of solution is 0.4 mol/L or 0.4M
No chemical reaction occurs. This is due to water molecules being very polar and and pulling out the sodium and chlorine ions once fully dissolved in water.
Resulting pressure is 13.6 atm.
<u>Explanation:</u>
Using Ideal gas equation, we can find the pressure of the gases formed in the reaction.
PV = nRT
Number of moles, n = given mass / molar mass = 20 g / 18 g/mol
= 1.11 moles
Volume, V = 2 L
Temperature, T = 25°C + 273 = 298 K
R = gas constant = 0.08206 L atm K⁻¹ mol⁻¹
P = nRT/V
= 1.11×0.08206 ×298 / 2
= 13.6 atm