Answer : The correct option is "record 10.00 ml in the notebook after using it."
Explanation :
If an instrument has "10 mL TD" written on it, that means the instrument is meant To Deliver (TD) 10 mL of volume.
Therefore the option that has 5.00 mL is not correct.
"+/- 0.01 mL" indicates the precision of the instrument. We know that no measurement is 100% accurate and there is always some uncertainty associated with any measurement.
Here, 0.01 indicates the uncertainty in the measurement.
When we have 0.01 mL , that means the instrument can record precisely to the hundredths place.
The more the significant figures, the greater is the accuracy of the measurement.
Therefore when we use an instrument that has "+/- 0.01 mL" written on it, we should record the reading as 10.00 mL
Answer:
20.95 g of caffeine, C₈H₁₀N₄O₂
Explanation:
From the question given above, the following data were obtained:
Number of molecules of C₈H₁₀N₄O₂ = 6.5×10²² molecules
Mass of C₈H₁₀N₄O₂ =?
From Avogadro's hypothesis,
1 mole of C₈H₁₀N₄O₂ = 6.02×10²³ molecules
Next, we shall determine the mass of 1 mole of C₈H₁₀N₄O₂. This can be obtained as follow:
1 mole of C₈H₁₀N₄O₂ = (8×12) + (10×1) + (4×14) + (2×16)
= 96 + 10 + 56 + 32
1 mole of C₈H₁₀N₄O₂ = 194 g
Thus,
194 g of C₈H₁₀N₄O₂ = 6.02×10²³ molecules
Finally, we shall determine the mass of caffeine, C₈H₁₀N₄O₂ that contains 6.5×10²² molecules. This can be obtained as follow:
6.02×10²³ molecules = 194 g of C₈H₁₀N₄O₂
Therefore,
6.5×10²² molecules = (6.5×10²² × 194) / 6.02×10²³
6.5×10²² molecules = 20.95 g of C₈H₁₀N₄O₂.
Therefore, 20.95 g of caffeine, C₈H₁₀N₄O₂ contains 6.5×10²² molecules
b. -5, -4, -3, -2, -1, 0, +1, +2, +3, +4, +5
<h3>Further explanation</h3>
Each orbital in an atom consists of 4 quantum numbers
n is the principal quantum number.
l is the angular momentum / azimuthal quantum number
ml, the magnetic quantum number
ms, the electron-spin quantum number
Value of n: positive integer
value of l: s = 0, p = 1, d = 2, f = 3 , ..(n-1)
ml value: between -l to + l
ms value: +1/2 or -1/2
So for L=5, mL value : -5 to +5
