Answer:
The geologist time scale was formed when scientists studied rock layers and index fossils worldwide. With this information, they placed Earth's rocks in order by relative age. Later, radioactive dating helped determine the exact age of the divisons in the geologic time scale.
This scale is organized by the 4.6 billion years of earth's history into sections based on important changes seen in the geologic record. The largest intervals are called eons, with each eon containing many millions of years.
In precambarian time the processes that affect Earth's surface have lessened the erosion on the surface. Earth was being hit by meteorites every second. Now there is water erosion and there wasn't back then. The surface changes have lessened over time.
Answer:
the weakest acid is B) HIO
Explanation:
pKa = - log Ka
the higher the value of pKa, the lower the dissociation, therefore, an acid will be stronger the lower its pKa.
a) HC2H3O2; Ka = 1.8 E-5
⇒ pKa1 = - Log (1.8 E-5) = 4.745
b) HIO; Ka = 23 E-11
⇒ pKa2 = - Log ( 23 E-11 ) = 9.638
c) HBrO; Ka = 23 E-9
⇒ pKa3 = - Log ( 23 E-9 ) = 7.638
d) HClO; Ka = 2.9 E-8
⇒ pKa4 = - Log ( 2.9 E-8 ) = 7.537
e) HCO2H; Ka = 63 E-5
⇒ pKa5 = - Log ( 63 E-5 ) = 3.200
from the values pKa, we places the acids from the weakest to the least weak:
1) pKa2; HIO (weakest)
2) pKa3
3) pKa4
4) pKa1
5) pKa5
Coal is mainly made of carbon and there’s oxygen in the air so this burns to produce carbon dioxide. Breathing it can really hurt your lungs.
Photosynthesis. Easy ;) have a nice day
