Answer:
The red arrow from igneous to sedimentary rock
Explanation:
When rocks are weathered and eroded, they become sediment. This sediment is later compacted and cemented to form sedimentary rock. Therefore, the red arrow going from igneous rock to sedimentary rock represents weathering and erosion.
The reactions of the human body are exothermic
The alkali metals can't exist alone in nature because of incomplete outermost shell of alkali metals.
<h3>What are the properties of alkali metals?</h3>
The alkali metals have the high thermal and electrical conductivity. It has high lustre, ductility, and malleability as compared to other materials. Each alkali metal atom has one electron in its outermost shell which make more reactive.
So we can conclude that the alkali metals can't exist alone in nature because of incomplete outermost shell of alkali metals.
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Answer:
Melting points are often used to characterize organic and inorganic crystalline compounds and to ascertain their purity.
Explanation:
Radio active decay reactions follow first order rate kinetics.
a) The half life and decay constant for radio active decay reactions are related by the equation:
Where k is the decay constant
b) Finding out the decay constant for the decay of C-14 isotope:
c) Finding the age of the sample :
35 % of the radiocarbon is present currently.
The first order rate equation is,
![[A] = [A_{0}]e^{-kt}](https://tex.z-dn.net/?f=%20%5BA%5D%20%3D%20%5BA_%7B0%7D%5De%5E%7B-kt%7D%20%20%20)
![\frac{[A]}{[A_{0}]} = e^{-kt}](https://tex.z-dn.net/?f=%20%5Cfrac%7B%5BA%5D%7D%7B%5BA_%7B0%7D%5D%7D%20%3D%20e%5E%7B-kt%7D%20%20)
t = 7923 years
Therefore, age of the sample is 7923 years.
