Valence shell
The number of electrons in the outermost shell of a particular atom determines its reactivity, or tendency to form chemical bonds with other atoms. This outermost shell is known as the valence shell, and the electrons found in it are called valence electrons.
Answer:
Option (B).
Explanation:
Mixture may be defined as the solution obtained by mixing of two or more substances together. Two different types of mixture are homogeneous mixture and heterogeneous mixture.
Homogeneous mixture may be defined as the mixture that has uniform composition throughout the mixture and cannot be separated easily by physical shaking process. Heterogeneous mixture are the mixtures that has different composition throughout the mixture and can be separated by simple shaking.
Thus, the correct answer is option (B).
Answer: Ecosystem Services
Explanation: Simply put,Ecosystem services refer to all the benefits that man enjoys from his relationship with the ecosystem.Ecosystem services are the benefits that people obtain from ecosystems. Ecosystem services are indispensable to the wellbeing of all people, everywhere in the world. They include provision,regulation and cultural services that directly affect people, and supporting services needed to maintain the other services. From the availability of adequate food and water, to disease regulation of vectors, pests, and pathogens, human health and well-being depends on these services and conditions from the natural environment.
We depend on nature for our survival – without healthy ecosystems, our drinking water isn’t clean nor is the air we breathe. Studies also show that people who spend time in nature tend to be happier than those that don’t. Being outdoor can even act as a natural anti-depressant. With industry and urban sprawl expanding at unprecedented rates, Ecosystem Services attempt to translate the benefits we receive from nature into economic terms so we can better understand the compromise we are making between nature and industrial development.
