18)
a. Ra
d. Ag
19)
a. C
b. Br
c. Mg
20)
a. S
b. Br
c. O
Sorry wasn’t sure about some of them in #18
Hope the notes are helpful.
Answer:
Glossopteris
Explanation:
Glossopteris is a fossil fern that helped support Wegener's hypothesis.
Hope this helps! Have a great day!
B is gas
The chemical element krypton is classed as a noble gas and a nonmetal.
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Answer : The specific heat (J/g-K) of this substance is, 0.780 J/g.K
Explanation :
Molar heat capacity : It is defined as the amount of heat absorbed by one mole of a substance to raise its temperature by one degree Celsius.
1 mole of substance releases heat = 92.1 J/K
As we are given, molar mass of unknown substance is, 118 g/mol that means, the mass of 1 mole of substance is, 118 g.
As, 118 g of substance releases heat = 92.1 J/K
So, 1 g of substance releases heat = 
Thus, the specific heat (J/g-K) of this substance is, 0.780 J/g.K
Answer:
Instrumental methods
surface analysis
high performance liquid chromatography
atomic spectroscopy
potentiometry
Classical methods
precipitation titration
gravimetric analysis
Explanation:
Instrumental methods of analysis are those analytical methods in which the responsibility of detection has been removed from human beings and placed on automated instruments while classical methods are those analytical methods in which the responsibility of detection remains the responsibility of human beings.
Many instrumental methods such as HPLC rely on computer screens as readout devices.