END OF YEAR 8 SCIENCE EXAM Flashcards
What nutrients does
the human body
require
vitamins, minerals, protein, fats, water, and carbohydrates.
What is the structure
and function of the digestive system?
breaks down food into simple nutrients such as carbohydrates, fats and proteins.
How can lifestyle choices affect our body?
affect energy metabolism, cellular growth, steroid metabolism, inflammatory mediation, DNA repair and immune function.
What is the structure
of the periodic table and how are elements arranged and grouped?
The chemical elements are arranged in order of increasing atomic number. The horizontal rows are called periods and the vertical columns are called groups.
What are the main groups in the Periodic Table?
groups 1 and 2 (s-block), and groups 13 to 18 (p-block).
How do groups of elements show trends in properties?
boiling point.
What is static charge and how are they generated?
Static electricity is the result of an imbalance between negative and positive charges in an object.
What is the nature of current, potential difference and resistance?
current is directly proportional to voltage but inversely proportional to resistance.
How do series and parallel circuits differ?
In a series circuit, all components are connected end-to-end to form a single path for current flow. In a parallel circuit, all components are connected across each other with exactly two electrically common nodes with the same voltage across each component.
How do magnets and electromagnets work?
when the coils of wire in an electromagnet have an electric current passing through them, the coils behave like a magnet.
What are solutions and what is solubility?
What is Solubility? The maximum amount of solute that can dissolve in a known quantity of solvent at a certain temperature is its solubility. A solution is a homogeneous mixture of one or more solutes in a solvent. Sugar cubes added to a cup of tea or coffee are a common example of a solution.
The nature of mixtures.
heterogeneous or homogeneous
How can we use evaporation to
separate solutions?
to separate components of a mixture with a dissolved solid in a liquid.
How can we use
Filtration to separate
solids from liquids?
The liquid particles are small enough to pass through the filter paper as a filtrate. The solid particles are too large to pass through the filter paper and stay behind as a residue.
What is
Chromatography used for?
enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis.
How we get energy form
food.
The stomach and small intestines absorb the glucose and then release it into the bloodstream.
The law of conservation
of energy
energy can neither be created nor be destroyed.
How is energy
transferred as heat?
by conduction, by convection, and by radiation.
Sources of energy.
coal, geothermal energy, wind energy, biomass, petrol, nuclear energy,
Work and power.
Work, Energy and Power - Definition, Examples, Formula, Units
Work is the energy needed to apply a force to move an object a particular distance. Power is the rate at which that work is done.
How do we know how much energy different appliances use?
The wattage of most appliances is usually stamped on the bottom or back of the appliance, or on its nameplate
How organisms are adapted to their environments
Structural and Behavioral Adaptations
The concept of evolution as a way pf adapting to changes in environment.
natural selection
What is variation and how is it important?
the variations in DNA sequences. It makes one organism different from the other organism. Variations are essential for natural selection.
What is natural selection?
the process through which populations of living organisms adapt and change.
What causes extinction?
overhunting or overharvesting; introduction of nonnative species, including the spread of disease; and habitat degradation or loss
How do metals react
with oxygen?
a metal oxide forms.
How do metals react
with acids?
Metal + acid → salt + hydrogen
What is displacement?
the change in position of an object.
Do metals react with
water?
Metal oxide and hydrogen gas is created when a metal and water reacts together.
How can we extract
metals?
dump leaching, heap leaching, tank leaching, or pressurized leaching.
What are the different types of rock found on Earth?
Igneous, Sedimentary & Metamorphic
What is the carbon cycle and how do humans affect it?
Burning fossil fuels, changing land use, and using limestone to make concrete all transfer significant quantities of carbon into the atmosphere.
How do you calculate speed?
speed = distance ÷ time.
How do you show motion on a graph?
the steeper the graph, the faster the motion.
Where do plants get their energy from?
the sun
During photosynthesis, plants trap light energy with their leaves.
How do leaves work?
turning sunlight into food.
Are there any other ways to release energy?
Engaging in physical activities such as running, dancing, playing sports, or practicing yoga
