The purpose of using distilled water in the cuvette of the spectrophotometer is to calibrate the instrument. It is generally considered that distilled water shows zero absorbance and 100 % transmittance. So, to zero out the absorbance of compounds other than the analyte being determined, distilled water is used as a blank.
If the unknown being determined is prepared using ethanol as the base solution, the blank used must be ethanol. This is because absorbance if any from the solvent, ethanol must be zeroed out as when the measurement of the actual unknown is being made, the absorbance of the solvent does not interfere.
Explanation:
1. subatomic particles.
2.proton, electron and neutron
3.The atomic mass of an element is actually the sum of the MASSES of protons and neutrons in AN atom of that element
4.An element's atomic number is equal to the number of protons in the nuclei of any of its atoms
5. Number of Protons = Atomic Number
Number of Electrons = Number of Protons = Atomic Number
Number of Neutrons = Mass Number - Atomic Number
For krypton:
Number of Protons = Atomic Number = 36
Number of Electrons = Number of Protons = Atomic Number = 36
Number of Neutrons = Mass Number - Atomic Number = 84 - 36 = 48
6. electron, lightest stable subatomic particle known. It carries a negative charge of 1.602176634 × 10−19 coulomb, which is considered the basic unit of electric charge. The rest mass of the electron is 9.1093837015 × 10−31 kg
7.The center of the atom is called a nucleus
8. Negatively charged particles are found in multiple layers outside the nucleus of the atom. These particles are called electrons, and they orbit in various energy levels around the atom's nucleus.
9. A charged particle is also called an ion
Answer:
2/3
Explanation:
Crystals structures can also be seen when two elements combines together and the perfect example is Al₂O₃ which is given in the question above. Just like it is given in the question above, the kind of arrangement in the crystal structure for Al₂O₃ is called HCP which stands for Hexagonally Closed Pack.
The aluminum ions which is in form of Al³⁺ occupies the two-third[2/3] positions while the position that the oxygen ion occupies is one[1].
Answer:
Hi, even though this is really not a question or an answer to a question.
Explanation:
Do you know if any of this stuff involves 6th grade?
Answer:
The mass ratio of zinc to sulfide is 85:42.
2.5559 kg of Zn are in 3.82 kg of ZnS.
Explanation:
a) Mass of zinc sulfide = 254 g
Mass of zinc in a zinc sulfide sample = 170 g
Mass of sulfide in zinc sulfide sample = x
254 g = 170 g+ x
x = 84 g
The mass ratio of zinc to sulfide:
b) Mass of zincsulfide sample = 3.83 kg
The mass ratio of zinc to sulfide is 85:42.
Let the mass of zinc and sulfide be 85x and 42x respectively:
85 x+ 42 x=3.82 kg
x =0.03007 kg
Mass of an zinc= 85x=85 × 0.03007 kg= 2.5559 kg
