Answer:
Mass of chemical = 1.5 mg
Explanation:
Step 1: First calculate the concentration of the stock solution required to make the final solution.
Using C1V1 = C2V2
C1 = concentration of the stock solution; V1 = volume of stock solution; C2 = concentration of final solution; V2 = volume of final solution
C1 = C2V2/V1
C1 = (6 * 25)/ 0.1
C1 = 1500 ng/μL = 1.5 μg/μL
Step 2: Mass of chemical added:
Mass of sample = concentration * volume
Concentration of stock = 1.5 μg/μL; volume of stock = 10 mL = 10^6 μL
Mass of stock = 1.5 μg/μL * 10^6 μL = 1.5 * 10^6 μg = 1.5 mg
Therefore, mass of sample = 1.5 mg
Both A and B are the answer.
surrounds the nucleus of an atom in various energy levels called orbitals.
Explanation:
Electrons surrounds the nucleus of an atom in various energy levels called orbitals.
According to the Bohr's model of an atom, the extra nuclear space is made up of electrons in specific spherical orbits called shells or energy levels.
- The region of a maximum probability of where an electron is located is sometimes referred to as an electron cloud or orbital.
- Electrons move round the nucleus in certain permissible orbits.
- An electron in an energy level posses a definite amount of energy associated with it at that level.
- Electrons moves through the energy levels by gaining or losing energy.
Learn more:
Bohr brainly.com/question/4986277
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