Atomic mass Na = 22.99 u.m.a
22.99 g ------------------ 6.02x10²³ atoms
175 g -------------------- ?? atoms
175 x (6.02x10²³) / 22.99 => 4.58x10²⁴ atoms
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Answer:
M is Li, X is boron, and Q is oxygen. MX is LiB, lithium bromide. QX is BO, boron oxide (not Body Odor).
Explanation: The atomic masses don't match exactly with those listed in the periodic table. Boron, Oxygen, and Lithium come the closest.
Lithium reacts with bromine since it happily donates it's single 2s electron to bromine's 4p orbital to fill bromine's 4s and 4p valence orbitals to go from 7 to 8 valence electrons, it's happy state.
Boron reacts with oxygen to form B2O3, which I'll happily write as O=BOB=O, since my name is Bob. This is more complex, but both elements want to move electrons around in order to reach a more stable electron configuration. Boron has 3 valence electrons and oxygen has 6. So each oxygen needs 2 electrons to fill it's outer shell and boron is happy to lose it's 3 valence electrons to reach an outer shell equiovalent to helium. So 2 borons contribute a total of 6 electrons, and the 3 oxygens have room for a total of 6 electrons to fill their outer shell.
Answer:
read it first
Explanation:
Population change is governed by the balance between birth rates and death rates. If the birth rate stays the same and the death rate decreases, then population numbers will grow. If the birth rate increases and the death rate stays the same, then population will also grow.
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This question does not contain the structures of the molecules. The structures in Daylight SMILES format are:
I. C1=CC=CC=C1C(=O)C
II. C1=CC=CC=C1CC=O
III. C1=CC(C)=CC=C1C=O
IV. C1=CC=CC=C1CCC
V. C1=CC=CC=C1C(C)C
The structures are also attached
Answer:
The structure of compound IV is consistent with the information obtained analysis
Proposed structures for the ions with m/z values of 120, 105,77 and 43 are (also attached):
C1=CC=CC=C1C(=[OH0+])C |^1:7|
C1C([CH0+]=O)=CC=CC=1
C1[CH0+]=CC=CC=1
C(#[OH0+])C
respectively
Explanation:
The IR peak at 1687 cm⁻¹ is indicative of an α unsaturated carbonyl carbon. While the 1H NMR singlet is of the methyl group next to carbonyl and the multiplet near 7.1 ppm is a characteristic peak of benzene. This data shows points towards structure I.
Mass spectrum peak at 120 m/z is of molecular ion peak. In the case of carbonyl-containing molecule, this peak is observable. The signal at 105 shows the loss of a methyl group next to the carbonyl. m/z value of 77 is the characteristic cationic peak of benzene, while the peak at 43 infers the formation of acylium ion (RCO+) due to α-cleavage. All this data agrees with the structure of acetophenone (Structure 1)
The data set is missing in the question. The data set is given in the attachment.
Solution :
a). In the table, there are four positive examples and give number of negative examples.
Therefore,
and

The entropy of the training examples is given by :

= 0.9911
b). For the attribute all the associating increments and the probability are :
+ -
T 3 1
F 1 4
Th entropy for
is given by :
![$\frac{4}{9}[ -\frac{3}{4}\log\left(\frac{3}{4}\right)-\frac{1}{4}\log\left(\frac{1}{4}\right)]+\frac{5}{9}[ -\frac{1}{5}\log\left(\frac{1}{5}\right)-\frac{4}{5}\log\left(\frac{4}{5}\right)]$](https://tex.z-dn.net/?f=%24%5Cfrac%7B4%7D%7B9%7D%5B%20-%5Cfrac%7B3%7D%7B4%7D%5Clog%5Cleft%28%5Cfrac%7B3%7D%7B4%7D%5Cright%29-%5Cfrac%7B1%7D%7B4%7D%5Clog%5Cleft%28%5Cfrac%7B1%7D%7B4%7D%5Cright%29%5D%2B%5Cfrac%7B5%7D%7B9%7D%5B%20-%5Cfrac%7B1%7D%7B5%7D%5Clog%5Cleft%28%5Cfrac%7B1%7D%7B5%7D%5Cright%29-%5Cfrac%7B4%7D%7B5%7D%5Clog%5Cleft%28%5Cfrac%7B4%7D%7B5%7D%5Cright%29%5D%24)
= 0.7616
Therefore, the information gain for
is
0.9911 - 0.7616 = 0.2294
Similarly for the attribute
the associating counts and the probabilities are :
+ -
T 2 3
F 2 2
Th entropy for
is given by :
![$\frac{5}{9}[ -\frac{2}{5}\log\left(\frac{2}{5}\right)-\frac{3}{5}\log\left(\frac{3}{5}\right)]+\frac{4}{9}[ -\frac{2}{4}\log\left(\frac{2}{4}\right)-\frac{2}{4}\log\left(\frac{2}{4}\right)]$](https://tex.z-dn.net/?f=%24%5Cfrac%7B5%7D%7B9%7D%5B%20-%5Cfrac%7B2%7D%7B5%7D%5Clog%5Cleft%28%5Cfrac%7B2%7D%7B5%7D%5Cright%29-%5Cfrac%7B3%7D%7B5%7D%5Clog%5Cleft%28%5Cfrac%7B3%7D%7B5%7D%5Cright%29%5D%2B%5Cfrac%7B4%7D%7B9%7D%5B%20-%5Cfrac%7B2%7D%7B4%7D%5Clog%5Cleft%28%5Cfrac%7B2%7D%7B4%7D%5Cright%29-%5Cfrac%7B2%7D%7B4%7D%5Clog%5Cleft%28%5Cfrac%7B2%7D%7B4%7D%5Cright%29%5D%24)
= 0.9839
Therefore, the information gain for
is
0.9911 - 0.9839 = 0.0072
Class label split point entropy Info gain
1.0 + 2.0 0.8484 0.1427
3.0 - 3.5 0.9885 0.0026
4.0 + 4.5 0.9183 0.0728
5.0 -
5.0 - 5.5 0.9839 0.0072
6.0 + 6.5 0.9728 0.0183
7.0 +
7.0 - 7.5 0.8889 0.1022
The best split for
observed at split point which is equal to 2.
c). From the table mention in part (b) of the information gain, we can say that
produces the best split.