Which force prevents protons from repelling each other inside a nucleus?
the gravitational force
the weak nuclear force
the electromagnetic force
<u>the strong nuclear force</u>
The original concentration is 5.1 × 10⁹ CFU / ml
In order to attain a countable plate, the number of CFU must be present in between 10 and 200 per ml.
Let us take 0.1 ml and dilute it to 1 ml.
This minimizes the concentration to 5.1 × 10⁹ × 10⁻¹ = 5.1 × 10⁸ CFU/ml
In order to minimize the concentration in between 10 and 200, it can be reduced to 5.1 × 10¹
The final concentration = 5.1 × 10¹ CFU/ml
Initial concentration = 5.1 × 10⁹ CFU/ml
Volume of sample with 5.1 × 10¹ CFU = 5.1 × 10¹ CFU × (1 ml / 5.1 × 10⁹ CFU)
= 1.0 × 10⁻⁸ ml
This is the volume to be taken to obtain countable value, 51 CFU.
Explanation:
Noble gas configuration is defined as the configuration which contains completely filled orbitals.
For example, oxygen atom when gain two electrons then it forms oxygen ion (
).
Atomic number of oxygen atom is 8 and so, its number of electrons will also be 8. But when it gain two electrons then it has total 10 electrons. Hence, electronic configuration of is as follows.
Since, there are completely filled orbitals in an ions. Therefore, it means this ion has a noble-gas configuration.
Thus, we can conclude that any specie which shows completely filled orbitals will have noble-gas configuration.
Answer:
HF is the acid
Explanation:
The Brønsted-Lowry theory defines the acids and bases in chemistry as follows:
An acid is the species that can donate a proton
A base can accept protons.
In the reaction:
HF(aq) + NH₃(aq) → NH₄⁺(aq) + F⁻(aq)
As you can see, HF can donate its proton to produce F⁻: HF is the acid
<em>In the same way, NH₃ is accepting a proton, NH₃ is the base.</em>
