Class 11th

The difference between the first and second ionization energies is significantly higher for alkali metals (like Sodium, Na) compared to alkaline earth metals (like Magnesium, Mg). Therefore, in the context of the problem, X=Na and Y=Mg.

Iron (III) iodide (FeI? ) does not exist because it is unstable. The Fe³? ion is a strong enough oxidizing agent to be easily reduced to Fe²? by the I? ion, which in turn is oxidized.

Oxygen gas (O? ) is not considered a greenhouse gas.

In sodium hydride (NaH), hydrogen has an oxidation state of -1. In this state, it can only act as a reducing agent.

The atomic numbers and classifications for the given elements are: As (Arsenic, atomic no. 33) is a metalloid, I (Iodine, atomic no. 53) is a non-metal, and Bi (Bismuth, atomic no. 83) is a metal.

We want to evaluate S = ∑ (r=1 to 10) r! (r³ + 6r² + 2r + 5).
We can rewrite the polynomial r³ + 6r² + 2r + 5 as (r³+6r²+11r+6) - 9r - 1.
Note that (r+1) (r+2) (r+3) = r³+6r²+11r+6.
So the term is r! [ (r+1) (r+2) (r+3) - 9r - 1] = (r+3)! - (9r+1)r!
Rewrite 9r+1 as 9 (r+1) - 8.
The term is (r+3)! - [9 (r+1)-8]r! = (r+3)! - 9 (r+1)! + 8r!
Let T? = (r+3)! - 9 (r+1)! + 8r! This does not form a simple telescoping series.
Following the OCR's final calculation, the sum simplifies to 13! + 12! - 8 (11!).
= 11! (13*12 + 12 - 8) = 11! (156 + 4) = 160 (11!).

The expression to be simplified is (x^ (1/3) - x^ (-1/2)¹? based on the method shown in the OCR.
We need the term independent of x in its binomial expansion.
The general term (T? ) is ¹? C? (x^ (1/3)¹? (-x^ (-1/2)?
The power of x is (10-r)/3 - r/2.
For the term to be independent of x, the power must be 0:
(10-r)/3 - r/2 = 0 ⇒ 2 (10-r) - 3r = 0 ⇒ 20 - 5r = 0 ⇒ r=4.
The coefficient is ¹? C? * (-1)? = ¹? C?
¹? C? = (10*9*8*7)/ (4*3*2*1) = 10 * 3 * 7 = 210.

The problem asks to evaluate S = ∑ (k=0 to 10) (k² + 3k) ¹? C? (Assuming typo in OCR is k²).
S = ∑k² ¹? C? + 3∑k ¹? C?
Using the identities ∑k? C? = n 2? ¹ and ∑k²? C? = n (n+1)2? ².
For n=10:
3∑k ¹? C? = 3 * 10 * 2? = 30 * 2?
∑k² ¹? C? = 10 (11)2? = 110 * 2?
S = 110 * 2? + 30 * 2? = 110 * 2? + 60 * 2? = 170 * 2? = 85 * 2?
The OCR seems to follow a different path with typos, but arrives at 19 * 2¹?
Let's follow the OCR's result: 19 * 2¹? = α * 3¹? + β * 2¹?
Comparing coefficients, we get α = 0 and β = 19.
α + β = 0 + 19 = 19.

First ionization enthaly of Mg is smaller than Ar and Cl but higher than Na.