Answer:5
Explanation:The pnictogen group, or nitrogen group, is located in column 15 of the periodic table. This family consists of the elements nitrogen, phosphorus, arsenic, antimony, bismuth, and ununpentium (N, P, As, Sb, Bi, and Uup, respectively). Each member of this family contains five valence electrons.
Pseudo-science is not considered real science because it is not testable.
Answer: Option A
<u>Explanation:</u>
Pseudoscience primarily includes beliefs, theories or practices that are somehow incompatible with the scientific facts. The pseudoscience can’t be tested on the basis of science.
Let’s take an example of astrology. Some people believe that stars and other celestial bodies draw a significant impact on their life i.e. Good or bad thing it's just because their stars are working either in a positive or negative manner.
But, this belief doesn’t have any well-proved or authentic background over which the whole concept can rely on. Hence, pseudoscience is not taken as a real science as a lack of strong proves.
<u>Answer:</u> The volume of stock solution needed is 90 mL
<u>Explanation:</u>
To calculate the molarity of the diluted solution, we use the equation:

where,
are the molarity and volume of the stock sulfuric acid solution
are the molarity and volume of diluted sulfuric acid solution
We are given:

Putting values in above equation, we get:

Hence, the volume of stock solution needed is 90 mL
Answer:

Explanation:
Hello,
In this case, for the dissociation of calcium fluoride:

The equilibrium expression is:
![Ksp=[Ca^{2+}][F^-]^2](https://tex.z-dn.net/?f=Ksp%3D%5BCa%5E%7B2%2B%7D%5D%5BF%5E-%5D%5E2)
In such a way, via the ICE procedure, including an initial concentration of calcium of 0.01 M (due to the calcium nitrate solution), the reaction extent
is computed as follows:

Thus, the molar solubility equals the reaction extent
, therefore:

Regards.