<h1><strong>CHANGES IN LIVING THINGS (GROWTH AND DEVELOPMENT)</strong></h1> CONTENT <ol> <li>Definition of Growth and Development</li> <li>Growth and Developmental Changes</li> <li>Characteristic Features of Developmental Stages</li> <li>Classifying Growth and Developmental Changes (Temporary and Permanent Changes)</li> <li>Factors Affecting Growth and Development</li> </ol>   <h2><strong>Definition of Growth and Development</strong></h2> Growth is the permanent increase in size of an organism due to increase in number of cells. Growth is brought about by cell division. Development is a series of orderly changes by which a living thing comes into maturity. It is a series of changes that occur during growth. It is a gradual process leading to maturation of organs and behaviour of individual like social, emotional as well as skill acquisition.   <h2><strong>Growth and Developmental Changes</strong></h2> The noticeable changes in the body size over time is termed<strong> growth change. Growth </strong>change can be determined by measure of height and weight at time intervals while developmental changes can be observed by appearance of certain characteristics features and capabilities. Development leads to transition from one stage of life to another e.g a baby develops from infancy to childhood, then to adolescence and to adulthood. Developmental changes are progressive and move from simple to complex.   <h2><strong>Characteristic Features of Developmental Stages</strong></h2> The developmental changes are characterized by certain features which include the following:

<h1><strong>CHANGES IN NON-LIVING THINGS</strong></h1> CONTENT <ol> <li>Types of Changes in Non-living Things</li> </ol>   <h2><strong>Types of Changes in Non-living Things</strong></h2> Non-living matter undergo changes i.e they can be made to change from one state to another. They can be made to form new substances. Changes in non-living things can be classified into physical changes and chemical changes.   <h2><strong>Physical Changes</strong></h2> Physical changes are changes in which no new substances are formed. A physical change is a temporary change, It is reversible. The composition of the new substance does not change when undergoing a physical change. Examples are: 1. Melting of candle wax. 2. Dissolution of salt in water to form a salt solution. Salt + Water <img class="alignnone size-full wp-image-14541" src="https://classhall.com/wp-content/uploads/2018/03/single-arrow.jpg" alt="right pointing arrow" width="77" height="7" /> Salt solution 3. All changes in state of matter are physical changes. Such as, vapourization of liquid to gases.

<h1>CHEMICALS</h1> CONTENT <ol> <li>Meaning of Chemicals</li> <li>Classification of Chemicals</li> <li>Chemical Safety</li> </ol>   <h2>Meaning of Chemicals</h2> Chemicals are substances with specific molecular composition. A chemical can be in form of gas, liquid, or solid. It can also be in simple or complex form. They can be in form of element, compound, and mixtures. <p style="text-align: center;"><img class="size-full wp-image-19641 aligncenter" src="https://classhall.com/wp-content/uploads/2018/06/mercury.jpg" alt="Mercury" width="353" height="228" /><strong>Mercury</strong></p> <span style="color: #008000;">Chemical elements are basic substances that are often used to make other products. Mercury is one of the few elements that are liquid at room temperature. This element is poisonous and can be absorbed through the skin.</span> <h2>Classification of Chemicals</h2> <h3>Classification Based on Uses</h3> <ol> <li>Pharmaceutical chemicals</li> <li>Nuclear chemicals</li> <li>Agrochemicals</li> <li>Industrial chemicals and</li> <li>Laboratory chemicals.</li> </ol> 1.<strong> Pharmaceutical Chemicals: </strong>They are chemicals formulated to act as remedy on living cells, they could be herbal or chemical synthesis. They are used for making of drugs. Such as antibiotics, antiseptics etc. 2.<strong> Nuclear Chemicals:</strong> They are chemicals that function based on the activities within the nucleus. Some of these chemicals can split or disintegrate (decay) through the process of radioactivity. It can be used for positive or negative purpose. E.g. it is used during X-ray. 3.<strong> Agrochemical:</strong> These are chemicals used for agricultural purposes. Examples are pesticides, herbicides, fertilizers, and organic manure.

<h1>CHEMICAL ELEMENTS AND COMPOUNDS</h1> CONTENT <ol> <li>Meaning of Element</li> <li>Elements and their Symbols</li> <li>Names of Elements Derived From the Latin Name</li> <li>Chemical Compound</li> <li>Nature of Elements</li> <li>Mixture</li> </ol>   <h2>Meaning of Element</h2> Elements are substances that cannot be broken down into anything else. Everything in the world are built up from these elements. There are about one hundred and twelve (112) elements known today. Scientists use short forms called symbols to represent elements as shown below. <h2>Elements and their Symbols</h2>

<h1><strong>ADAPTATION OF ORGANISMS TO THEIR HABITATS</strong></h1> CONTENT <ol> <li>Meaning of Adaptation</li> <li>Characteristics of Organisms Found on Land</li> <li>Characteristics of Organisms Found in Water</li> </ol>   <h2><strong>Meaning of Adaptation</strong></h2> Adaptation means special features that help an organism to live and survive in a particular habitat. Every living thing on earth belongs to one habitat or the other because it is always interacting with some biotic and abiotic components such as energy, water, air (oxygen), food, carbon dioxide and suitable living conditions. For example, there are certain species of plants and animals that can survive only in rain forest habitat and not in the desert and vice versa. <br> <h2><strong>Characteristics of Organisms Found on Land</strong></h2> The following are the characteristics of organisms found on land: