Explanation:
2H2(g) + O2(g) → 2H2O(l )
I believe that the answer is 11.5
The mass decay rate is of the form

where
m₀ = 3000 g,the initial mass
k = the decay constant
t = time, years.
Because the half-life is 30 years, therefore

After 60 years, the mass remaining is

Answer: 750 g
Answer:
The bottom layers of the rock could have formed before life occurred.
Explanation:
The bottom layers of the rock could have formed before life occurred because there is no fossil is present. If there is life at that time so the fossils are present at the bottom layer so the absence indicates that is no life present at that time. The bottom layer is older than the upper layer so that's why fossils of bacteria are found in the upper layer of the rock.
Answer:
C. Because bacterial fossils are found only in the upper layers, scientists can conclude that these bacteria evolved towards the end of Precambrian time.
There’s two different types of answers for this question so I just put both of them. Hope it helps : )
Answer:
Fusão: a substância volta do sólido para o líquido. Condensação: a substância muda de um gás para um líquido. Vaporização: a substância muda de líquido para gás. Sublimação: a substância muda diretamente de um sólido para um gás sem passar pela fase líquida.