Le Science in pillole O Appunti di scienze A cura delle insegnanti Allida De Candido e Cristiana Ziraldo

1. I.P.S.I.A “ Zanussi” di Pordenone Le Science in pillole O Appunti di scienze A cura delle insegnanti Allida De Candido e Cristiana Ziraldo Summary • Home

2. Subject Area: Science Class Level and Course Title: first Class / Science of Earth Unit of Study: States of Matter States of matter • The students are introduced to a unit involving States of Matter • Objective • to known the three states of matter (solid, liquid and gas); • to list the general properties of each state; • to describe them in terms of shape and volume; • to list everyday examples of each state; Summary • Home

3. Forms of matter Matter is anything that takes up space and has weight Matter is anything that takes up space and has mass or weight. Matter exists in three forms or states - solid, liquid and gas. Solids can be soft or hard Can you think of something on the Earth that is hard? Rocks Minerals Liquids can be On the Earth Gas can be ( Summary • Home

4. Solid state Particles in a solid have fixed position. They are close together. If they are positioned in a regular structure they may form crystals. The forces holding them in position are strong, so solids have their own shape. At 0 K (-273°C) the particles are stationary. At temperature above 0 K the particles vibrate but cannot move from their positions. As the temperature increases the vibrations become more energetic.

5. Liquid state • Liquids take the shape of the container into which they are put. • Particlesin a liquid are stillfairly close together. • The forcesbetween particles arenot as strong as in a solid and allow groups of particles to slide over each other. This is why liquids canflow. • Particles in a liquid thereforedo not have a fixed position. • Liquidsdo not have a shape of their own. • They take the shape of the container into which they are put. • These groups of particlesmove around slowly. • Because the liquid particles move around slowly the dye gradually mixed with the water. Summary • Home

6. Gas state The distances between gas are relatively large. Therefore they are almost completely free of forces and so spread out and fill any container into which they are placed. They are moving around at high speeds (approx. 500 m/sec at room temperature). Gases diffuse (spread out and mix) more quickly than liquids. The directions in which they move have no pattern: they are random motions (speed and direction). The gas particles inside this container are continually bouncingoff the sides. It is these collisions with the sides of the container that create the pressure inside the container. Summary • Home

7. What affects the pressure in a gas There are several factors that will affects the size of the pressure in a gas. Mass If the volume of the container is decreased, the particles will have less distance to travel between collisions. There will therefore be more collisions per second, i.e. the pressure will increase. Volume If more gas particles are pushed into the container there will be more frequent collisions and so the pressure will increase. Temperature If the temperature of a gas is increased its particles will move faster, there will be more collisions each second and there will again be an increase in pressure. Summary • Home

8. Attributes of matter To sum up Summary • Home

9. Changes of states In the daily lives, there are a variety of matter in the different states. Objectives To be able to classify and describe the changes of state To know haw matter changes and what causes matter to change Summary • Home

10. Melting Freezing Changes of State of Matter There are different changes that can take place. Water, for example, can change from water to ice, which is calledfreezing. Freezing is what happens whena liquid changes to a solid. Water can change from ice to water, which is calledmelting. Melting is what happens when a solid changes to a liquid. * Summary • Home

11. evaporation condensation Water can also change from a water to steam, which is called evaporation. Evaporation is what happens when a liquid changes to agas. Water can change from steam back to water, which is called condensation. Condensation occurs when gas changes into a liquid. WaterGas There are some substances which can go from being a solid, directly to the gas state, which is called sublimation. Solid carbon dioxide, commonly known as Dry Ice, bypasses the liquid state altogether when it changes to a gas. Summary • Home

12. Sublimation Deposition The last change of state is matter going from a gas, directly to the solid state, which is called deposition. Water vapours in the air during winter fall in the form of snow, SolidGas Summary • Home

13. Cause of changes Energy Energy is either lost or gained during a change of state. * When energy is applied to a solid, the tightly packed particles of matter begin to move around, flowing over each other. The result is the movement of liquid. The shape becomes indefinite. The volume, however, does not change, because the particles are still part of one another. * When energy is applied to a liquid, the particles that make up a liquid, begin to move about so rapidly, that they can no longer hold themselves together. The result is the movement of a gas. The shape is indefinite, and the volume becomes indefinite. The reverse happens to gas when energy is taken away. Water vapour, for example begins to liquefy as it cools. Remember the cool mornings when fog is dense and close to the ground? What happens? Dewdrops form. The water vapours in the air cool to form liquid drops on grass. * When energy is taken away from liquid, the particles in the liquid slow down to low movement. The resulting solid, has definite shape and definite volume. Summary • Home

14. To sum up Cooling Deposition?=brinamento condensation freezing melting evaporation sublimation Heating Summary • Home

15. Test 1) When a solid changes into a liquid, it is called ...... vaporization melting evaporation 2) When a solid changes directly into a gas, it is called...... sublimation evaporation 3) When a gas changes into a liquid, it is called ...... solidification melting condensation 4) Matter in a solid state has . . . . . volume and . . . . . . shape. ____ no definite _____ no definite ____ a definite ______ a definite ____ a definite ______ no definite 5) The states of matter are the following: solids, liquids, gases, plastics. True False 6) States are also known as ? phases phrases frases 7) Which phase of matter does not take the shape of the container it is in? solid liquid Summary • Home

16. 8) Liquids are hard to compress. Gases are easy to compress. True False 9) When solids reach their melting point they become ...... liquids gases 10) What happens when a gas reaches condensation point? it becomes a solid it becomes a liquid 11) What is evaporation? When liquids turn into vapour When solids turn into vapour 12) What state / phase can fit into any container of any size and any shape? a gas solid liquid and solid 13) Gas and vapour means the same. True False 14) Which state can hold their own shape? a solid a liquid a gas Summary • Home

17. 15) Which state of matter resists very strongly if you try to change its shape? gas solid 16) When a liquid changes into a solid, it is called ...... melting freezing condensation 17) Solidification is when a gas changes into a solid. true false 18) Matter in a ...... has a ...... volume and ...... shape. gaseous state ___ no definite ___ no definite liquid state _____ no definite ___ definite solid state _____ no definite ___ no definite 19) When water freezes or when water becomes a vapour is it still the substance: water? a) yes b) no 20) Pick the correct statement: a)Solids become gases at their melting points b)Solids become liquids at their melting points Summary • Home