Our Natural Resources Science – Chapter 1 Class 8 1

Contents Module 1 1.1 Introduction 1.2 Types of resources 1.3 Water 1.4 Soil 1.5 Forest 1.6 Wild life 1.7 Fossil fuel 1.8 Minerals 2

1.1 Introduction What are natural resources? Natural resources occur naturally within environments Natural resource is often characterized by amounts of biodiversity and geo diversity existent in various ecosystems. Any material which is part of earth and satisfy human need and add value is called as resource. Example: rocks, minerals, soil, rivers, plants & animal. Human is a resource because developing his skill, he can develop other resource by adding value to the physical material . 3 3

1.2 Types of resources Biotic : Resources which are living in nature. Example: Forests ,Animals etc. A biotic : Resources which are non-living in nature. Example: Air ,Water etc. OTHERS Renewable : Resources which can be replenished easily. Example: Sunlight 4

1.3 Water Water is a unique natural resource. It is the most critical limiting factor for many aspects of life such as environmental stability, biodiversity. There is no substitute for water. It is irreplaceable resource. In nature water exists in 3 different forms. Solid- ice Liquid- water Gaseous- vapor 5

Activity 1.1 : Distribution of water 6

1.4 Soil Soil provides support and nutrients for plant growth Erosion Soil absorbs water and releases the same for use by plants. Water gets purified as it percolates through the soil. Erosion Is the movement of sediment and rocks to new places. Pic for compound : http://www.google.co.in/search?q=Image+for+H2&hl=en&source=lnms&tbm=isch&sa=X&ei=Bck5Uda1KYrkrAfIqIHACg&ved=0CAcQ_AUoAQ&biw=1510&bih=772#hl=en&tbm=isch&sa=1&q=Image+for+H2+molecule&oq=Image+for+H2+molecule&gs_l=img.3...4028.8340.2.8543.23.21.1.1.1.1.173.2073.11j10.21.0...0.0...1c.1.5.img.bLXnQbUVlhU&bav=on.2,or.r_qf.&bvm=bv.43287494,d.bmk&fp=602bb7f7ed54f5e2&biw=1510&bih=772&imgrc=o5E_Hati-03NoM%3A%3BTKZtY3EIPO5tIM%3Bhttp%253A%252F%252Fwww.3dchem.com%252Fimagesofmolecules%252Fwater.jpg%3Bhttp%253A%252F%252Fwww.3dchem.com%252Fmoremolecules.asp%253FID%253D234%2526othername%253Dhydrogen%252520hydroxide%3B349%3B311 Pic for Carbon : http://www.google.co.in/search?hl=en&q=Isotop+Carbon+Image&bav=on.2,or.r_qf.&bvm=bv.43287494,d.bmk&biw=1510&bih=772&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=aZg8UZqNBMzHrQe2l4DoDA#imgrc=Ty1xCZv0D9mrCM%3A%3BU9k0wcmOLfOCZM%3Bhttp%253A%252F%252Fwww.microseeps.com%252Fhtml%252Fimages%252Ffaq%252FCSIA_FAQ_1.gif%3Bhttp%253A%252F%252Fwww.microseeps.com%252Fhtml%252Fcsia_faq.html%3B380%3B276 7 7

1.5 Forests Forests are renewable natural resources that have innumerable contributions to the environment. Forests maintain water cycle. They provide habitat for wild animals. They prevent soil erosion. Forests provide timber and other products. They indicate wealth. In the last 20-30 the rate of deforestation has increased and created imbalance in the ecosystem. 8

1.6 Wild Life The wild life term is used to describe species of plants and animals living in the wild. Human activities such as hunting , poaching and capturing have severely affected wild life, leading to the extinction of many valuable species. Wild life sanctuaries are built to protect wild life. 9 9

(Nonrenewable source of energy) 1.7 Fossil fuels (Nonrenewable source of energy) Coal, petroleum products and natural gas represent a kind of resource collectively called fossil fuels. They are result of photosynthetic activity of green plants, which were existing millions of years ago. They got submerged with earths’ crust and formed fossil fuels. Types of coal deposit: Anthracite, Lignite, Bituminous Coal Today our consumption rate is in excess of the rate of formation of fossil fuels. In one day we consume what the Earth has taken thousands of years to form! Hence, fossil fuels are considered as non renewable. 10 10

(Nonrenewable source of energy) 1.8 Mineral resources (Nonrenewable source of energy) Mineral is a substance that is naturally found in the Earths’ crust and is not formed from living matter. They are formed due to Earths’ geological processes over millions of years. Hence they are non renewable. Minerals like gold, iron, copper, aluminum and non metals (stone, salt ,sand) are extracted and processed for human use. This process of extraction and processing is called mining. Mining has become intense and widespread in recent years, causing serious environmental degradation. 11 11