Answer:
( B) They all have their valence electrons in the same type of subshell.
Explanation:
With each period, a new shell is added to the atom.
Further, the groups are classified based on the type of subshell the last electron enters and number of valence electrons.
For all elements of same group, the last electron enters the same type of subshell.
Say, for group 1, last electron enters s orbital and they have 1 valence elctron.
for group 17, last electron enters p orbital and they have 7 valence electrons.
(A) and (D) are wrong because, energy level of the valence electrons is determined by the principle quantum number n and l and not by the type of subshell(only l) they enter.
(C) if the valence electron enters p orbital, then the elements will be placed in the p- block.
when Cl2 is dissolved in water it generates ClO which is a good oxidizing agent since it gives out atomic oxygen. but dissolution of F2 cannot generate atomic oxygen since F is more electronegative than O
The grams of glucose are needed to prepare 400g of a 2.00%(m/m) glucose solution g is calculated as below
=% m/m =mass of the solute/mass of the solution x100
let mass of solute be represented by y
mass of solution = 400 g
% (m/m) = 2% = 2/100
grams of glucose is therefore =2/100 = y/400
by cross multiplication
100y = 800
divide both side by 100
y= 8.0 grams
Answer:
smallest is O then Se then K then Cs.
Explanation:
These trends exist. elements tend to get smaller as it completes it's shell since there is more attraction when it is complete. plus the further down the periodic table you go the bigger it is. there are more electrons which repulse each other and make it bigger.
Answer:
[NO] = 1.72 x 10⁻³ M.
Explanation:
<em>2NO(g) ⇌ N₂(g)+O₂(g),</em>
Kc = [N₂][O₂] / [NO]².
- At initial time: [NO] = 0.171 M, [N₂] = [O₂] = 0.0 M.
- At equilibrium: [NO] = 0.171 M - 2x , [N₂] = [O₂] = x M.
∵ Kc = [N₂][O₂] / [NO]².
∴ 2400 = x² / (0.171 - 2x)² .
<u><em>Taking the aquare root for both sides:</em></u>
√(2400) = x / (0.171 - 2x)
48.99 = x / (0.171 - 2x)
48.99 (0.171 - 2x) = x
8.377 - 97.98 x = x
8.377 = 98.98 x.
∴ x = 8.464 x 10⁻².
<em>∴ [NO] = 0.171 - 2(8.464 x 10⁻²) = 1.72 x 10⁻³ M. </em>
<em>∴ [N₂] = [O₂] = x = 8.464 x 10⁻² M.</em>
