Answer:
Measuring distances to stars through stellar parallax. Measuring distances to stars through the moving cluster method. Astronomers measure the temperature of a star by looking at the star's color and its spectrum. The apparent brightness of a star tells how bright it seems to us
Explanation:
Answer:
Canonical structures of a chemical specie explain its observed properties from a valence bond theory perspective.
Explanation:
Resonance is a valence bond concept introduced by Linus Pauling to explain the observed properties of certain chemical species such as bond lengths, bond angles, bond order , etc.
There are certain chemical species for which a single chemical structure does not suffice in explaining its observed properties. For instance, the bond order in CO3^2- is about 1.33. Its bond length, shows that the C-O bond present in CO3^2- is neither a pure C-O single bond nor a pure C-O double bond. Hence the structure of CO3^2- is 'somewhere in between' three contributing canonical structures as shown in the image attached to this answer. The resonance structures of NO3^- are also shown.
Answer:
9.7 x 10⁻⁴
Explanation:
HA ⇄ H⁺ + A⁻
C(eq) 0.0174 10⁻²·³⁹ 10⁻²·³⁹
=0.0041M =0.0041M
Ka = [H⁺][A⁻]/[HA] = (0.0014)²/(0.0174) = 9.7 x 10⁻⁴
Science, Economics, Statistics, Finance, and many other areas of life where we are measuring things to a certain level of accuracy.
I don’t know the answer either