The human “family tree” may be better described as a “family bush,” within which it is impossible to connect a full chronological series of species, leading to Homo sapiens, that experts can agree upon.
The most accurate means of determining the purity of a substance is through the use of analytical methods. These methods, widely used in different industries, mostly involve chemical analysis, which can pinpoint the presence, identity and amount of impurities in the sample. The most simple chemical methods include gravimetry and titration. There are also the more advanced light-based or spectroscopic methods, such as UV-VIS spectroscopy, nuclear magnetic resonance and infrared spectroscopy. Chromatographic methods, such as gas chromatography and liquid chromatography, can also be used. Other methods used in testing the purity include mass spectroscopy, capillary electrophoresis, optical rotation and particle size analysis.
-basically nerdy talk for using machines controlling chemicals or other atoms to pinpoint any impurities
Answer:
0.007 M
Explanation:
pH is defined as the negative logarithm of the concentration of hydrogen ions.
Thus,
pH = - log [H⁺]
The expression of the pH of the calculation of weak acid is:-
Where, C is the concentration = ?
Given, pH = 3.45
So, for 
, 
C = 0.007 M
The atomic orbitals of the central atom mix to form hybrid orbitals are one s and three p.
<h3>Which atomic orbitals are used to form hybrid orbitals?</h3>
Pauling supposed that in the presence of four hydrogen atoms, the s and p orbitals form four equivalent combinations which he called hybrid orbitals.
<h3>How many bonds does PF5?</h3>
Phosphorus pentafluoride has 5 regions of electron density around the central phosphorus atom (5 bonds, no lone pairs).
The resulting shape is a trigonal bipyramidal in which three fluorine atoms occupy equatorial and two occupy axial positions.
Learn more about PF5 here:
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