Science

• Ecosystem refers to an area where plants,animals and other organisms interact with one another
• Scientific knowledge is acquired through an ongoing process of making observations, formulating hypotheses and gathering evidence to either support or refute those hypotheses.
• Observation involves using our senses, such as sight, hearing, touch, taste, and smell, to gather information about something.
• Non-metals are brittle and cannot be hammered or rolled into thin sheets.
• Tropical rainforests are found near the equator and receive high amounts of precipitation throughout the year.
• Hypothesis is a tentative explanation that can be tested by collecting data and analyzing it.
• Observations are made by using our senses (seeing, hearing, smelling, tasting, touching) or instruments such as microscopes, telescopes, thermometers, etc.
• Hypothesis is a tentative explanation that can be tested by collecting evidence from experiments or observations
• The periodic table is organized by atomic number (the number of protons) and electron configuration (how electrons are arranged).
• Theory is an idea that has been supported by many pieces of scientific evidence over time
• Ceramic: poor conductor of heat, hard, fragile, high melting point, can be moulded, durable
• Metal: shiny, good conductor of electricity, good conductor of heat, can be moulded, flexible
• Glass: transparent, poor conductor of electricity, poor conductor of heat, can be moulded, high melting point, fragile
• Plastic: lightweight, durable, can be moulded, low melting point, poor conductor of electricity, poor conductor of heat
• Fibres: can be spun into threads or woven into fabrics, absorbant, poor conductor of electricity, poor conductor of heat
• Electrical Conductors: copper and iron, allows electrical current to flow through (conductivity)
• Electrical Insulators: rubber and plastic, does not allow electrical current to flow through(insulation), low electrical conductivity
• Electrical conductivity = how easily electric current can pass through a material
• Conductors of heat: metal, allow heat to pass through easily (thermal conductivity)
• Plastic is a heat insulator
• Thermal conductivity = how easily heat can pass through a material
• Melting point: the temperature when a substance changes from solid to liquid
• Boiling point: The temperature at which a liquid turns into a gas.
• Strength: ability to support a heavy load without changing its shape permanently
• Thermal conductivity = how well a substance or material transfers heat energy from one place to another
• Hardness= the resistance to wear and tear
• Flexibility = ability to bend without breaking and return to its initial size and shape after bending
• Density = the amount of matter an object has in proportion to its volume
• Density: mass/volume
• Mass: kilograms(SI unit), grams, tonnes
• Volume: cubic metre(SI unit), cubic centimetre or mililitres or litres
• 1ml=1cm3

  1l=1000cm3

  1m3=1,000,000cm3
• 1kg=1000g

  1 tonne=1000kg or 1,000,000g
• Length: metre(SI unit), cm, km
• 1cm=10mm

  1m=100cm

  1km=1000m or 100,000cm
• kg/m3(SI unit), g/cm3

  mass per unit volume
• Density affects the ability to float or sink
• less dense objects float on denser mediums
• Melamine: light, strong, harmful when consumed, the chemical composition is similar to that of milk’s
• Elements: the basic building blocks of living and non-living things, they cannot be broken down into simpler substances, represented by chemical symbols, 118 known elements(periodic table of elements)