just say this: the green color is from the mold
Answer:
Explanation:
Half life of Nobelium-253 is 97 seconds . That means after every 97 seconds half of the Nobelium amount will be disintegrated .
Time taken in bringing the sample to laboratory = 291 seconds
291 second = 291 / 97 half life
n = 3
N = 
N₀ is original mass , N is mass after n number of half life.
N = 5 mg x 
= .625 mg
Only 0.625 mg of Nobelium-253 will be left .
The answer is; B
Initially, the earth’s atmosphere was mainly filled with carbon dioxide and methane. However, with the evolution of photosynthetic organisms, the composition of the atmosphere changed to be mainly oxygen. This geological time is referred to as the great oxygenation event. The high oxygen levels resulted in oxidation of most the upper lithosphere.
The answer is; B
During this time, the organism on earth began to evolve and live on land. Therefore these geologic events are marked by fossilized of dead primitive organisms such as archaebacteria within the early rocks
Answer:
Na2Co3
Explanation:
Molar mass: 105.9888 g/mol
Melting point: 851 °C