(Originais Teachy 2024) - Question Hard of Sciences

In the solutions used in laboratories, the concentrations of ions $$\mathrm{H}_{3} \mathrm{O}^{+}$$ are usually small and a simple way to express the hydrogenionic concentration of a solution is through pH. Solutions of weak acids and bases present, in solution, an equilibrium between the various particles and, in this case, we have the equilibrium constant, that is, the ionization constant. A solution of $$1.10^{-3} \mathrm{mol}^{-1}$$ of bromoacetic acid $$\left(\mathrm{BrCH}_{2} \mathrm{CO}_{2} \mathrm{H}\right)$$ has an ionization constant equal to $$6.3.10^{-5} \mathrm{e}$$ and a solution of $$1.10^{-3} \mathrm{mol}^{-1}$$ of 4-chlorobenzoic acid $$\left(\mathrm{ClC}_{6} \mathrm{H}_{4} \mathrm{CO}_{2} \mathrm{H}\right)$$ has an ionization constant of $$1.0.10^{-4}$$. Given the following statements, I. 4-chlorobenzoic acid has a higher $$\mathrm{pH}$$ than bromoacetic acid. II. Bromoacetic acid is weaker than 4-chlorobenzoic acid. III. Since the concentrations are equal, both acids have the same $$\mathrm{pH}$$. IV. Bromoacetic acid has a higher $$\mathrm{pH}$$ than 4-chlorobenzoic acid. v. 4-chlorobenzoic acid is weaker than bromoacetic acid. It is verified that only ii and iv are correct.

Plants are very important living beings for our world, and each part of them has a special function. The root helps the plant stay in place and take water from the soil, the stem holds the plant up and carries water to the leaves, the leaves use sunlight to make food, the flower attracts insects and animals to aid in reproduction, the fruit protects the seeds and helps the plant spread. With that in mind, choose a plant you know, like a flower you have at home or a tree from school, and describe a function for each part of that plant: root, stem, leaf, flower, and fruit. Explain why each of these parts is important for the plant to live and grow healthily.

Exotic and invasive species are those that, due to human transportation, are taken to other ecosystems and end up becoming a non-native species, which can affect local biodiversity. For example, the red swamp crayfish (Procambarus clarkii) was introduced in Brazil in the mid-20th century for food production. What is the biggest risk of this species to Brazilian biodiversity?

The lunar eclipse can also be called 'Blood Moon' due to its reddish color during the event. This coloration occurs due to the light from stars and planets passing through the Earth's atmosphere and reaching the lunar surface, being called diffuse light or twilight light. What are the main elements present in the Earth's atmosphere responsible for this coloration?