The statement which is true about the reactivity of element with 1S²2S²2P⁶3S¹ is
it is reactive because it has to lose one electron to have a full outermost energy level.
<u><em>Explanation</em></u>
- <u><em> </em></u>Element with 1S²2S²2P⁶3S¹ electron configuration is a sodium metal.
- sodium has one electron in the outermost energy level.
- for sodium to have a full outermost energy level ( 8 electrons) it loses the 1 electron in 3S¹ to form a positively charged ion. (Na⁺)
Answer: dilute
Explanation:
A concentrated solution which is used to prepare solutions of lower concentrations by diluting it with addition of water.
A dilute solution is one which contains lower concentration.
Using Molarity equation:
=concentration of stock solution = 0.150 mol/L
= volume of stock solution = 10.0 ml
= concentration of dilute solution = ?
= volume of dilute solution = (10.0+90.0) ml = 100.0 ml


As the concentration is less than the original concentration, the solution is termed as dilute.
To solve this problem,
we can use the Henderson-Hasselbalch Equation which relates the pH to the measure
of acidity pKa. The equation is given as:<span>
<span>pH = pKa + log ([base]/[acid]) ---> 1</span></span>
Where,
[base] = concentration
of C2H3O2
in molarity or moles
<span>[acid] = concentration of HC2H3O2 in molarity or moles</span>
For the sake of easy calculation, let us assume that:
[base] = 1
[acid] = x
<span>
Therefore using equation 1,
4.24 = 4.74 + log (1 / x)
<span>log (1 / x) = - 0.5
1 / x = 0.6065 </span></span>
x =
1.65<span>
The required ratio of C2H3O2 /HC2H3O2 <span>
is 1:1.65 or 3:5. </span></span>
Use your head or a formula website.