Answer:
4 Fe + 3 O₂ → 2 Fe₂O₃
Explanation:
Let's start with the oxygen.
Reactants - 2
Products - 3
What number do 2 and 3 have in common? 6.
Put a 3 in the reactants and a 2 in the products to balance the oxygen.
Fe + 3 O₂ → 2 Fe₂O₃
Now let's look at the iron.
Reactants - 1
Products - 4
Put a 4 in the reactants to balance the iron.
4 Fe + 3 O₂ → 2 Fe₂O₃
The equation is balanced. Hope that helps.
Answer:
In terms of carbon and energy sources, all cyanobacteria are photosynthetic autotrophs.
Explanation:
Cyanobacteria are prokaryotic microorganisms, that is, they have cellular structure that corresponds to the cell of a bacterium. As for carbon absorption and energy acquisition, all cyanobacteria are autotrophic and photosynthesizing, presenting photosystems I and II but not organized in chloroplasts, such as plants. Due to the presence of these chlorophyll-rich pigments, phycocyanins and phycoerythrins, they have been called cyanophytic algae for many years.