Matter Everything around us is matter. Matter is anything that has mass and occupies space. Matter can exist in three forms or states. The three states of matter are a. Solid e.g. brick, table, you (human) etc. b. Liquid e.g. water, vinegar etc. c. Gas e.g. air, cooking gas etc. liquids solids Gas Child blowing air (a gas) into balloon. a Properties of Solids 1. They have fixed shapes. 2. They have fixed volumes. 3. They have fixed sizes. 4. The molecules are very close. Properties of Liquids 1. They have fixed volume. 2. They have no fixed shape; liquids take the shape of their containers. 3. The molecules are not as close as that of solids 4. Liquids flow. Properties of Gases 1. They have no fixed shape. 2. They have no fixed volume. 3. The molecules are far apart. 4. They take the shape and volume of their containers. Gas Liquid Solid Change in States of Matter Matter changes from one state to the other when heat is added or removed. Examples of changes in states of matter include: a. Melting: This is the process by which a solid changes to a liquid when heated, e.g. ice melts to form water. The melting point of water is 0⁰C. b. Evaporation: This is the process by which liquids change to gas when heated, e.g. water changes to steam or vapour. The boiling point of water is 100⁰C. c. Condensation: This is the process by which gas changes to liquid when cooled. Steam changes back to water when the temperature gets lower than 100⁰C. d. Freezing: This is the process by which liquids change to solid e.g. water changes to ice when cooled at a temperature of 0⁰C. e. Sublimation: This is the process by which a solid changes directly to the gas state without going through the liquid state. Examples are camphor, air fresheners etc. Ice melts to form water when the temperature increases above 0℃ Melting When solid wax is heated up it melts and changes to Liquid. Freezing is when a liquid changes to solid when cooled. Water changes to solid at 0℃ • Freezing Condensation Steam changes back to water when it is cooled Evaporation When water gets heated up to 100℃ it changes to gas. A solid can change directly to gas. This is called Sublimation When we measure length we measure how long something is. You can measure the length of ANYTHING! Standard method is the acceptable method of measuring length The standard units of length are: Millimetres (mm) Centimetres (cm) Metres (m) Kilometres (km) Old and New Methods of Measuring Length 1. 2. 3. a) b) c) d) e) Measurement is the act of finding out the size, weight or quantity of something. The length of an object is a measure of how long or short the object is. The olden methods of measuring length were by the use of: Hand span Arm length Cubit Foot Stride etc. 5. Modern instruments used to measure length are: a. Ruler b. Measuring tape or tape rule c. Meter rule d. Micrometer screw gauge e. Vernier Calipers The S.I. unit of length is the meter. Other units are centimeter, kilometer, etc. Mass and Weight • The weight of an object tells us how heavy or light the object is. It is the amount of force exerted by an object due to gravity. • The standard unit of measuring weight is called Newton (N) • The mass of an object is the quantity of matter it contains. • The standard unit for mass is kilogram (Kg) • The instruments used to measure the mass and weight of objects include: • Bathroom scale • Chemical balance. • Beam balance. • Spring balance Differences between mass and weight Other items to measure liquids are: Volume of Liquids and Irregular Objects 1. Volume is the amount of space inside an object or the amount of space an object can occupy. 2. The volume of liquids is measured with a measuring cylinder. 3. Other instruments in measuring volume are: a. Measuring cup / jug b. Beakers c. Calibrated containers like bottles, cup, jug etc. 4. The standard unit for measuring volume is liter (L). 5. The volume of irregular objects can be determined by using the displacement principle. This means that when an object is immersed in water, it will displace a volume of water equal to its own volume. Volume or Capacity? Before we begin our work on volume and capacity, let’s make sure we understand what these two words mean. This measuring jug measures up to 500ml. We say that it has a capacity of 500ml. Capacity is the total amount of liquid that a container can hold. Gas Liquid Solid Gas Liquid Garden Tool Uses 1. Head Pan Used for carrying things such as grass, seeds, tools, seedlings and manure around the farm. 2. Watering Can Used for wetting plants especially in the dry season. 3. Hoe Used for – weeding. - making seed beds, ridges and mounds. - digging holes for planting. 4. Cutlass Used for - cutting trees, weeding, digging holes for, planting, etc. 5. Sickle It is a knife used for harvesting certain cereal crops such as rice, millet, sorghum and grass. 6. Go To Hell It is also a knife used for harvesting crops that are far away from the ground. 7. Shears Used for trimming or pruning plants. 8. Hand Trowel Used for digging holes and transplanting seedlings. Solid Diagram 9. Hand Fork Used to loosen soil especially around seedlings. 10. Rake Used for - leveling seed beds. - gathering weeds and other rubbish together. 11. Spade Used for - making mounds. - digging. - parking items such as soil and manure into containers. 12. Shovel Used for - making mounds. - digging. - parking soil, manure, etc into containers. 13. Pick Axe Used for breaking hard soil surfaces. 14. Garden Fork Used for loosening hard soil surface 15. Wheel Barrow Used for carrying soil, manure, harvested crops, seeds/seedlings, etc from one place to another. 16. Axe Used to cut woods, harvest timber etc. Kitchen scales can be used to measure small quantities of food usually up to 22 or 33 kg. The units are divided into kilograms and grams. Scales for measuring larger quantities of food (like vegetables or fruit) are sometimes seen in shops or markets. It can measure weight from 00 to 10 kg. Bathroom scales can be analog or digital (like the scale on the left). They are used to measure a person's weight and can measure weight from 0 to 150 kg. Bathroom scales usually show units in kilograms and grams. Larger analog scales are often used in hospitals to measure a person's weight. These can also measure weight between 0 and 150 kg. Flat electronic scales, called platform scales, can be used to measure bulky objects like suitcases (at the airport) or dogs (at the vet). Weighbridges are used to measure very large objects like trucks. The truck drives onto a special strip of road that is connected to a digital scale. The scale operator (shown in the picture on the left) then reads off the truck's weight in tonnes. What ’s the MATT ER ? Solids Materials in a solid state keep their shape unless a force is applied to them. Liquids Materials in a liquid state take the shape of the container they are in. Gas Gas Materials in a gaseous state can spread out to completely fill the container or room they are in.
