(Originais Teachy 2023) - Question Hard of Sciences

The ozone layer, located in the stratosphere, is responsible for filtering most of the ultraviolet radiation emitted by the Sun. Its role is crucial in protecting life on Earth, as excessive exposure to this radiation can cause serious damage to the skin and contribute to the development of skin cancer. However, the action of chemicals released into the atmosphere, such as chlorofluorocarbons (CFCs), has led to a process of ozone layer depletion, making it thinner and less efficient. Considering this context, answer: 1. Explain what CFCs are and how they are related to the destruction of the ozone layer. 2. Discuss the possible consequences for the planet if the depletion of the ozone layer continues at the current rate, considering the interactions between the ozone layer and the different terrestrial and marine ecosystems.

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?

You must have noticed that the materials we use in our daily lives can change when placed in different situations. For example, water can change its form when heated to make tea, or what happens to fruit when left out of the refrigerator for too long. Think of a material you know and explain how it could change if placed in four different situations: (1) exposed to strong sunlight, (2) placed in the freezer, (3) mixed with another material that reacts with it, and (4) cut into very small pieces. Write about the changes this material could undergo and what causes this change, explaining what happens at the particle level of the materials.