science exam

What do astronomers use to measure distances and how many kilometres make up to one?

Astronomers use astronomical units AU to measure distances within the solar systems and 150,000,000 km make up one AU

What do astronomers use for measuring longer distance such as distance between stars and how many kilometers?

They use light years, which is equal to 10,000,000,000,000 km

What is what type of galaxy is the Milky Way?

Spiral galaxy

Galileo Galilee invented what thing

He invented the telescope. He observed the mountains craters on the moon, the moons of Jupiter, the faces of Venus for the first time.

What makes the solar system?

The sun, the eight plants and their moons billions of other smaller objects all of these celestial objects that orbit the sun

To become a planet, a celestial object

Be an orbit around a star have enough mass to be pulled into a stable spear by gravity and dominate its orbit

Dwarf planets

The orbit the sun and have a spiracle shape, but they don’t dominate their orbits

Asteroid belts

Asteroids are small celestial objects made of rock and metal too small to be considered a planet. They lie in an area between the orbits of Mars and Jupiter, Called asteroid belt.

Meteoroid

Piece of metal or rock in the solar system that’s smaller than an asteroid and in outer space

What’s a meteor?

When a meteor ride enters earths atmosphere, causing friction to burn up and creating a streak across the sky is a meteor

Meteorite

When a meteor crashes into the ground because it doesn’t burn up completely

Comet

chunks of ice duster rock that Orbit t the sun cheap from the sun makes it turn into a gas called a coma Solar wind pushes it creating a tail

Stars

Hot gas body that produces its own light and energy

They seem to move from east to west in the northern hemisphere and rotate around one point: Northstar or Polaris

All stars form from a massive cloud of interstellar, gas and dust called a nebula made of mainly hydrogen and helium

How do stars form?

Stars form in a nebula Cloud of helium , and hydrogen gas and dust

Gravity forces the nebula to collapse and create a protostar

when the core reaches 15,000,000°C nuclear fusion begins hydrogens into helium

The star that produces a light and energy from fusion

stars mass will determine its lifespan massive stars burn faster, and have shorter lives

Sun

Is an average size star only see big because of how close it is to earth it provides energy needed for life made up of layers of gas, mostly hydrogen and helium

Planets, composure, size, density rotation, and distance

Colour and meaning

Red stars are the coolest orange and yellow stars are cool to medium blue stars are hottest

Solar prominences and solar flares

Arches of glowing gas anchor to the sun

Stay connected to the sun

Solar flares are burst of energy that travels through space

Earth, rotation, and AXIS

Rotation is an object that spins on its own AXIS one rotation for earth is 24 hours earth AXIS is tilted the portion of the Earth that faced the sun, experienced daylight and the other side experience night

Revolution

Earth revolution around the sun is 365.25 days

Force of gravity

The greater the mass, the stronger it’s gravitational pole the gravitational force of our son is strong enough to keep earth in its orbit

The geocentric model is a theory that

The planets revolved around an earth in a earth centred solar system

Heliocentric model/theory is

The sun is the centre of the solar system a sun centred solar system

Reasons for seasons

Since the Earth’s AXIS is tilted the Earth is closest to the sun. The northern hemisphere is tilted away from the sun, and we experience winter, and as the Earth revolves around the sun, the northern and southern hemisphere experience the seasons when the Earth is farthest from the sun, the northern hemisphere is pointed towards the sun and we experience summer.

What is a star map? Do stars move and change constellations positions overtime

Map of the night sky that shows relative positions of constellations and stars are always moving to the Earth and their shapes will change over time

Celestial Spear

Celestial spear extends around the Earth divided into the northern and southern hemisphere by the celestial equator, which is an extension of the earths equator

Views of the night sky

Night sky changes with the seasons as the earths revolution around the sun Different constellations are visible at different times of the year, which is why we see a different Night in summer then in winter

Year-round constellations

Circumpolar stars Never set and always visible closest celestial POLE like the Northstar, which is near the north celestial pole

Particletheory of matter

All matter is made up of different kinds of particles

Different substances are made up of differnt kinds of particles

Particles are always in random constant motion

Particles moves faster as temp icreases

Particles attract eachother

Pure substance

Made up of 1 type of particle

Mixture

Made up of more than 1 type of particle

Mechanical mixture

Heterogeneous a mixture partciles are distinguishableor non-uniform

Solution

Homogenous particles are not easily distinguishable or uniform

Alloy

A solid solution of two or more metals physically bonded

Physical property

Property that can be observed or measured without changing the substance

State colour viscosity mallealibility lustre texture clarity hardness ductility conductivity density

Qualitative property

Something that is described

Quantitative property

Something that is measured

Characteristic physical property

Properties that are unique to a substance like melting point density Boiling point solubility electric conductivity

Density

Amount of matter per unit value

Chemical property

How a substance reacts and changes into a new substance

Reactivity with water

Reactivity with oxygen

Physical change

No new substance is produced easy to reverse

change in size change in shape changing in state making a solution

Chemical change

New substance is produced hard or impossible to reverse

Changing colour changing an odour

Precipitate

A solid that forms from two liquids chemically

Element

Pure substance made up of only one type of atom like H O

Compound

Made of idenitcsl molecules 2 or more differnt elements bonded

Molecules are 2 or more atoms bonded tgh h2o

Metal

A metal that is usually shiny good conductor of heat and electricity

Nonmetal

Dull, not strong Poor conductor of heat in electricity

Metalloid

Element that has properties of both nonmetal and metal also known as semiconductor

Chemical family/group

Vertical column on the periodic table

Alkali metals

Group one most reactive because of one valence electron

Alkaline earth metals

Group 2

Halogen

Group 17

Noble gases

Not reactive because of full valence shield group 18

Period

Horizontal row of the periodic table

Atom

Small particle of an element like one hydrogen atom

Isotope

Lighter or heavier version of the element

Ion

Atom w electric charge bc it gain or lost electrons

Diff between anion and cation

Anion gains electrons negative charge

Cation loses electrons positive charge

Valence electrons

Electrons in the outermost shell

Molecule

Two or more atoms joined together

Chemical formula

Shows which elements and how many elements are in a formula such as H2O

Molecular element

electrons are shared between two or more of the same element like H2 O2

Molecular compound

Nonmetals bonded together sharing electrons like H2O

Lewis diagram

Standard atomic notation

Ionic compound

Metal and nonmetal gain/lose electrons

Ionic bond

When a metal and a nonmetal gives up an electron/gains

Covalent bond

When nonmetals share electrons making a molecular element like h2 o2

Pattern in the periodic table

Atomic number increases left to right and atomic mass

Same family has same valence electrons similar chemical physical properties and reacts similarly

Reactivity

Metals Reactivity decreases as we move left to right and increases as we move up to down

Non metals Reactivity increase as we move left to right and decrease as we move up to down

• What is current electricity?

Controlled flow of electrons through a conductor

We are able to control

What is an electric circuit?

Continuous path in which electrons can flow

What do electric circuits have?

Energy source conductor load switch

What is energy source?

Where electrons come from like battery

Conductor

Where electrons flow through like wires

Load

Changes electric energy to something useful

Switch

Controls the flow of electrons

What is electrical energy?

Energy that is made by the flow of electrons and electric circuit measured in joules

What is the current?

Rate of whihc electrons flow past a specific point

Measure and current

An anmetre is a device used to measure electric current unit ampere

Direct current

Dc flows in one direction and come from a cell (battery)

Alternate current

Ac alternates in in direction and comee from electrical outlets

Voltage or potential difference

The difference in electrical energy between 2 points in a electrical circuit also called voltage

Where must a volt metre be connected?

Voltmeter must always be parallel to a load or energy source

Resistance

Ability of a material to slow the flow of electrical current (ohms)

Four key factors that affect resistance

Some substance resists the flow of electron than others

The longer a wire the more resistant

The thinner a wire the more resistant

The warmer the wire more resistant

What is a resistor?

Device that slows/reduces the flow of electric current

What is a series circuits

Only has 2 path for electrons to follow all loads must be on and working at the same time

What haooend when more loads are added to a circuit series

They Will receive less current and bulbs will get dimmer

What happens if you add more loads to a parallel circuit?

The current will be increased in the lightbulb will not get dimmer but stay the same

Parallel circuit

Circuit that has more than 1 pathway for electron so if one stops working or one is added the current will increase bc each loads recieve electrical current on separate pathways

Law electric charges

Opposite charges attract like charges repel

All objects and materials usually have what type of charge

Neutral

What is friction?

when two objects are rubbed together and electrons are transferred

electrostatic series

The higher on the list will always lose electrons and become positively charged. The object lower on the list will gain those electrons and become negatively charged.

Charging by a conduction

charging by conduction is when a charged object touches a neutral object, and the neutral object takes on the same charge as the charged object

What is grounding?

Grounding is when excess charge is removed by connecting an object to the Earth. The Earth balances the charge by adding or removing electrons.

What are insulators and examples?

Materials that prevent the movement of electrons non-metals water

What are conductors and examples?

Material that allows the movement of electrons examples of good conductors are metals like silver, copper, gold, magnesium, and fair conductors are saltwater human skin water vapour

If you use an insulator to touch a conductor that is carrying electric electricity, will you receive a shock

No electricity should not cannot pass through the insulator from the connecter keeping you safe from receiving a shock