A substance has a density of 4.5gmL. What is this in kgL? Report your answer with two significant figures.
1 answer:
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Answer:
9
Explanation:
The structure of fluorophore used in the experiments has been drawn in the attachment. And from the drawing counting we can say that there are 9 sp2-hybridized carbon atoms present. Fiuorophores are a fluorescent chemical compound that can re-emit light upon light excitation. Normally used to produce absorbance and emission spectra.
Answer:
A scandium-48 nucleus undergoes beta-minus decay to produce a titanium-48 nucleus.
.
Explanation:
There are two types of beta decay modes: beta-minus and beta-plus.
In both decay modes, the mass number of the nucleus stays the same.
However, in a beta-minus decay, the atomic number of the nucleus increases by one. In a beta-plus decay, the atomic number decreases by one.
Each beta-minus decay releases one electron and one electron antineutrino. Each beta-plus decay releases one positron and one electron neutrino.
Look up the atomic number and relative atomic mass for the element scandium.
- The atomic number of
is
.
- The relative atomic mass of
.
This question did not specify whether the decay here is beta-plus or a beta-minus. However, the relative atomic mass of this element can give a rough estimate of the mode of decay.
Each element (e.g, ) can have multiple isotopes. These isotopes differ in mass. The relative atomic mass of an element is an average across all isotopes of this element. This mass is weighted based on the relative abundance of the isotopes. Its value should be closest to the most stable (and hence the most abundant) isotope.
The mass number of scandium-48 is significantly larger than the relative atomic mass of this element. In other words, this isotope contains more neutrons than isotopes that are more stable. There's a tendency for that neutron to convert to a proton- by beta-minus decay, for example.
The atomic number of the nucleus will increase by 1. . That corresponds to titanium. The mass number stays the same at
. Hence the daughter nucleus would be titanium-48. Note that two other particles: one electron and one electron
and one antineutrino
(note the bar.) The neutrino helps balance the lepton number of this reaction.
Answer:
What mass (g) of barium iodide is contained in 188 mL of a barium iodide solution that has an iodide ion concentration of 0.532 M?
A) 19.6
B) 39.1
C) 19,600
D) 39,100
E) 276
The correct answer to the question is
B) 39.1 grams
Explanation:
To solve the question
The molarity ratio is given by
188 ml of 0.532 M solution of iodide.
Therefore we have number of moles = 0.188 × 0.532 M = 0.100016 Moles
To find the mass, we note that the Number of moles = from which we have
Mass = Number of moles × molar mass
Where the molar mass of Barium Iodide = 391.136 g/mol
= 0.100016 moles ×391.136 g/mol = 39.12 g