Flashcards
Semester 2 Science Flashcards
Cards in this deck (11)
- 1Science FlashcardsScience Flashcards
- 2Physical and Chemical Properties:Physical Properties:
-Describes a substance in terms of what you see. Testing a substance for its physical properties does not destroy the substance, or change it into anything new
-E.g state of matter, boiling and freezing point, appearance, density, how hard or brittle it is, solubility, ability to let heat or electricity pass through it
Chemical Properties:
-Describes how a substance reacts with other substances. A new substance is formed in the process, often with very different properties
-E.g burns of explodes in oxygen (combustion), rusts or corrodes, rate of reaction - 3Solids, Liquids and Gases:Solids:
-Fixed shape and does not flow (the particles are strongly bonded to each other)
-Incompressible (the particles cannot be compressed because they are so close together there is almost no room between them)
-Particles expand when heated and contract when cooled (heating causes the particles to vibrate quicker, making them spread further apart and expand. Cooling slows the vibrations and the opposite happens)
-Liquids:
-Flow to take the shape of their container (bonds are strong but loose enough to allow the particles in liquids to slide over one another)
-Incompressible (same as solids)
-Particles expand when heated and contract when cooled (heating causes the particles to move over each other faster and cooling is the opposite)
Gases:
-Often invisible (particles are spread so far apart that you can't see the gas)
-Compressible (particles are spread so far apart that there is plenty of vacant space between them. This space allows the particles to be pushed closer together)
-Spreads to fill the container (no bonds between the particles. Travel until they hit a wall) - 4Plasma:Plasma:
-Gas like state
-Only exists at temperatures above 6,000 degrees
-Commonly found on stars and lightning - 5The Particle Model:The Particle Model:
-A model that attempts to explain the properties of a substance
-Uses following ideas: all substances are made up of tiny particles too small to see even with a normal microscope, even if it is a very small amount the particles always have energy and are moving, the particles move about more and move faster when heated, the closer the particles are to one another, the stronger the attraction
-Shows what the particles are doing in the solid, liquid or gas - 6Indirect Evidence:Indirect Evidence:
-Observations made without sight
-Diffusion: the process of a smell spreading through the air - 7Changing State:Adding Heat:
-Melting: the process in which heat causes a solid to turn into a liquid e.g ice cube to water
-Melting Point: the temperature at which a solid melts
-Evaporation: the process in which heat causes a liquid to change into a gas e.g water to vapor
- Boiling: type of evaporation that only happens at the boiling point
-Boiling Point: the temperature at which something boils
-Sublimation: the process of changing from a solid to a gas without going through the liquid stage e.g dry ice
Removing Heat:
-Freezing: when heat is lost and a liquid turns into a solid
-Freezing Point: the temperature something freezes
-Condensation: when a gas loses heat and changes into a liquid
-Deposition: when a gas turns into a solid without going through the liquid stage - 8Density:Density:
-Is the physical property that determines whether a substance sinks, floats or bubbles up through water and other liquids
-Measures how much matter is packed into a space
-Particles in solids are usually packed together more closely than they are in liquids, making them denser than liquids of the same material
-When heated, the particles in a solid spread further apart, causing the substance to expand slightly. The substance takes up more space, so the density decreases. The less space it takes up, the more density it has.
-Density is measured in grams per centimetre cubed (g/cm3) - 9Mass, Weight and Volume:Mass:
-Is the amount of matter in an object
Volume:
-Is the amount of space a substance takes up
Weight:
-Is the name given to the pulling force of gravity on an object - 10How to Calculate Density:-Volume of Regular Solids: lXwXh (Formula: V=lwh)
-Volume of Liquids: mL or L
-Density of Solids: D=g divided by cm3
-Density of Liquids: D=g divided by mL
-Calculating Density: D=m divided by v
-Example: A block of wood 3cm on each side has a mass of 27g. What is the density of the block?
Mass= 27g
Density=?
Volume=lXwXh
=3x3x3
=27cm3
D=m divided by v
=27 divided by 27cm3
=1g/cm3
-Remember the triangle
-Volume of Irregular Solids: Drop the object into a measuring cylinder and the amount it rises by is the volume - 11Mixtures, Solutions, Suspensions and Colloids:A mixtures is:
-A substance made from two or more substances or pure chemicals that have been stirred together e.g liquid and liquid mixture
-3 types of mixtures: Solutions, Suspensions and Colloids
Solutions are:
-Groups of molecules that are mixed up in a completely even distribution e.g sugar and water solution
A suspension is:
-Where one substance does not dissolve in another e.g sand and water
Colloids:
-Mixture made of particles smaller than a suspension but bigger than a solution e.g milk
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- Flashcards on Semester 2 Science Flashcards, created by Ariana Hannaford on 19/10/2020.
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- Ariana Hannaford
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