Science Flashcards

Flashcards on Astronomy, Space, Chemistry, Electricity and Ecology

Astronomy

The study of space and what is beyond Earth.

Astronomical Unit (AU)

160,000,000 km; the distance from earth to the sun

perihelion

When the earth is closest to the sun; Also called the long axis. It is 147 000 000 km away from the sun.

aphelion

When the earth is farthest from the sun; Also called short axis. It is 150 000 000 km away from the sun.

Equinoxes

Happens twice a year when the earth is tilted, facing the side, meaning the tilt isn’t facing towards or away from the sun. There are 12 hours of daylight and 12 hours of night during these times

Solstices

Happens twice a year when the earth is either tilted towards or away from the sun.

Luminous

An object that creates/produces its own energy that gets converted into different forms like light and heat

Non-Luminous

Objects which cannot produce their own energy.

Satellites

Objects in space which orbit or circle around a much bigger object

Universe

everything that has been made/exists; All matter and energy

Galaxy

A system of stars, stellar remains, and Nebula (gas and dust in space), bound (held together) by gravity.

Geocentric Model

First model where the Earth was in the middle and everything revolved around it

Heliocentric Model

Second model where the sun was in the middle and the earth, planets, moon, and everything revolved around it

Umbra

the dark inner shadow from the earth

penumbra

the pale outer shadow from the earth

corona

the ring around the moon during a solar eclipse

Nuclear Fusion

hydrogen atoms clashing together to create energy

Solar Flare

tiny flames coming out of the corona

Solar prominence

large sheets of glowing gases moving from the chromosphere

Nuclear Fusion

Hydrogen atoms colliding together to become fused, and turn into heavier elements

Luminosity

The movements of a star’s energy

Spectroscopy

One of the most important tools used by astronomers where light is broken into its components and used to find info about composition, temperature, magnetic field and age of a celestial body

Matter

Anything that takes up space and has a mass

Pure Substance

Made up of one type of particle, the same throughout, definite composition and can only be separated by chemical means

Mixture

2 or more pure substances combined together and more than one phase can be seen and it may be able to be physically separated

Homogeneous

Often referred to as solutions where 2 substances combined but only one phase can be seen

Heterogeneous

2 or more substances combined, 2 phases/states can be seen, physical separation is possible and has various compositions

Suspension

The heavier particles settle at the bottom meaning you have to shake it

Colloid

Contains very small particles that combine together. You can’t see the particles, they are too small but they are there

Emulsion

Many phases combined together and make one thing

Malleability

Can be hammered or bent into different shapes

Hardness

Describes how resistant a surface is to being scratched

Luster

Describes whether matter is shiny or dull

Viscosity

Describes how well a liquid flows

Ductility

Can be spun or drawn into long thin wires

Solubility

The ability of a substance to be dissolved

Opaque

Cant see through it at all

Transparent

Can see through clearly

Translucent

Can be seen through slightly (cloudy)

Density

The amount of matter per unit volume

Melting point

Point at which a substance melts

Boiling point

Point at which a substance boils

Freezing point

Point at which a substance freezes

Qualitative Observations

Uses words to describe a substance

Quantitative

Uses numbers and units to describe matter

Chemical properties

Describes how matter behaves in a chemical reaction

Chemical Change

New substances form that have different properties from the original substance

Physical Change

When a substance goes through physical changes, no new substances are formed, only shape, size, or form has changed

Periodic Table

Arranged in 1869 by Dimitri Mendeleev by increasing atomic mass

Metals

Shiny, solid, silvery metals that are great conductors of heat and electricity

Nonmetals

Located on the right side of the staircase and can be liquid or gas or solid at room temperature and insulators

Metalloids

Have properties of both metals and nonmetals

Alkali Metals

Row 1 of the periodic table, shiny, silvery, soft metals that are most reactive

Alkaline Earth Metals

Row 2 of the table, easily found in nature, fairly reactive and almost always appears as a compound

Halogens

Row 17 of the table, most are gases at room temperature and most reactive nonmetals

Noble Gases

All gases at room temperature and non reactive- inert gases

Protons

Positively charged, found in the nucleus and are heavy

Neutrons

Neutral or no charge, found in nucleus, are heavy (like protons)

Electrons

Negatively charged, found in electron cloud, very light and move fast

Valence electrons

Electrons found in the outermost electron shell/orbit that are important for bonding

Chemical Bonds

Creating compounds (2 or more elements combined) involves valence electrons

Static Electricity

A stationary charge will build up on an object through contact

Current Electricity

Electrons moving along a path creating a circuit

Conductors

A substance that allows electrons to flow through it freely

Insulators

A substance that will hinder the flow of electrons through it

Grounding

Process of connecting an electrical system to the earth’s surface

Charging by friction

Need an electrostatic series and all objects begin as neutral, whichever object is higher on the list will lose their electrons and give to the other object. The objects are now positive and negative instead of neutral

Charging by Conduction

Involves contact between a charged object (+ or -) and a neutral object, After contact both objects with be the same charge (electrons transfer)

Charging by Induction

Involves no contact between a charged object and a neutral one, the charged object (+ or -) is brought close to, but not touching, the neutral object and the object is charged by induction will have the opposite charge of the charged object

Four parts of a circuit

Power source, connecting wire, load (device) and control device (switch)

Series Circuit

1 path only for electrons to flow, in the shape of a square where components are in line

Parallel Circuit

More than 1 path for electrons to flow through, in the shape of a rectangle where there is independent control of devices in different branches of flow

Open Circuit

No electron flow and non operative

Closed Circuit

Allows for flow and devices are operational

Voltage (or potential difference)

The force/push applied to electrons as they move around a circuit (energy) measured in Volts

Current

The amount of electrons moving past a point in a circuit at a given time (speed) measured in Amps

Resistance

The measure of how much a conductor fights the flow of electrons measured in Ohms (R)

Ohm’s Law

States that the current flow through a conductor between 2 points is proportional to the voltage

Electrical efficiency

If an electrical device was perfect, all the electrical energy would be converted into intended output energy (E out) and some of the energy will always be converted to thermal energy

Why would the fuse blow?

If the electrons in the circuit dont have any work to do then the fuse would blow.

Habitat

place where an organism lives on land, water, or air

Atmosphere

Extends 600 km above the surface of the earth made up of several layers -eg. Troposphere weather occurs here

Lithosphere

Made up of 2 outer layers: crust and upper mantle consists of plates that move slowly on a viscous layer called the asthenosphere

Hydrosphere

All of the water on earth, 70% of the earth’s surface

Biosphere

Area within the the atmosphere, lithosphere and hydrosphere where all living things exist

Biotic

living things

Abiotic

non living things

Transpiration

Plants exhaling h2o vapour into the atmosphere

Nitrogen Fixation

Lightning is a massive static electrical discharge in soil that nitrogen fixes bacteria through

Denitrifying Bacteria

a type of bacteria that remove nitrogen components from solid waste and decaying organisms

Population Density Dependant

Factors that affect population growth due to the density of the population

Population density independent

Factors that affect members of the population regardless of the population density

Community

Different species living in the same ecosystem

Predation

Something chases, catches and eats another living thing

Competition

2 different organisms that rely on the same resource (food, water)

Symbiosis

Relationship between 2 organisms that live together in close contact

Fertilizers

Chemicals that are used to increase the growth and production of plants

Pesticides

Chemicals that are designed to kill pests (insects and animals)

Litter

Made of decomposed grasses and leaves (source of nitrogen) and protects soil by limiting temperature change in soil and helps to reduce water loss by evaporation

Top Soil

Made up of small rocks, decayed animals and plant matter - “humus” is decayed matter (source of nitrogen)