Science

Chemistry

Table of Elements

The periodic table, created by Dmitri Mendeleev, is a compilation of the foundations of what everything around us is made of. There are currently 118 known elements on the table.

Element

A pure substance that can't be broken down by regular chemical means

Compound

A pure substance made of 2 or more different elements

Patterns

The metals are at the left of the periodic table, while non-metals are at the right.

Alkali Metals

An element in group 1 of the periodic table, they are highly reactive.

Alkaline Earth Metals

An element in group 2 of the periodic table, they are shiny and silvery metals. They are also highly reactive but not as much as the alkali metals.

Halogens

An element in group 17 of the periodic table, they are very reactive and rarely found in elemental form.

Noble Gases

They are unreactive non-metals. They contain full Valence shells and are mostly non-toxic

Metalloids

They are found along the "staircase" of the periodic table, and contain characteristics of metals and non-metals.

Hydrogen

Non-metal, but put in the alkali metal column, but put into the alkali group because of their atomic number. Hydrogen has no neutrons.

Theories of the Atom

An Indivisible Particle - The Atom

Made around 400 BC by Greek philosopher Democritus, talked about all matter being able to be divided into smaller pieces until an indivisible particle is reached (atom). He proposed atoms are of different sizes, in constant motion and separated by empty space

Aristotle

Created around 450 BC by Greek philosopher Aristotle. The theory was that all matter is made up of 4 substances, earth, water, air and fire and have 4 qualities dry, wet, cold and hot. This theory was accepted for almost 2000 years.

Billiard Ball Model

Created by John Dalton in 1807, he proposed that all matter is made up of tiny indivisible particles called atoms, all atoms of an element are identical. Atoms of different elements are unique and atoms are rearranged to form new substances in chemical reactions, but are never created or destroyed

Thompson's experiments-the electron

Created by J.J Thompson in 1897, he proposed that particles could be emitted by very hot materials. He concluded that particles must be negatively charged and they were called electrons. His theory was that atoms contain negatively charged electrons, and the rest of the atom is a positively charged sphere since atoms are neutral, negatively charged electrons are evenly distributed throughout the atom

The Gold Foil Experiment

Created by Ernest Rutherford in 1909. He theorized that the centre of an atom has a positive charge (nucleus), it contains most of the atoms' mass but occupies a very small space. The nucleus is what made some particles bounce back. The nucleus is surrounded any a cloud of negatively charged electrons. Most of the atom is empty space.

Explain the Periodic Table

Atomic number

Is the number of protons in an atom's nucleus

Atomic mass/Mass number

Is the mass of an atom in atomic mass units (u)/the number of protons and neutrons in an atom's nucleus

Finding the number of neutrons

x= Atomic Mass - Atomic Number

Bohr-Rutherford Diagram

Properties of Matter

Physical and Chemical Properties

Physical Properties

A characteristic we can determine using our 5 senses and/or measuring instruments

Gives us info of what a substance is like

Qualitative Properties

A property of substance that isn't measured by numerical values, such as colour, odor, texture, etc

Quantitative Properties

Freezing, Melting, & Boiling Point

Freezing Point: The point where the temperature turns a liquid into a solid

Melting Point: The point where the temperature turns a solid into a liquid

Boiling Point: The point where the temperature turns a liquid into a gas

A property of substance that is measured by numerical values, such as temperature, height, mass, etc

Chemical Properties

A characteristic of a substance that we know has changed if its composition is also changed.

The Particle Theory of Matter

All matter is made up of tiny particles that have empty spaces between them

Different substances are made up of different kinds of particles

Particles are in a state of constant motion

The particles of a substance move faster as the temperature increases

Particles attract one another

Matter

Pure Substances

A substance that is only made up of 1 type of particle

Mixtures

A substance that is made up of 2 or more different particles

Solutions

Alloys

A solid solution of 2 or more metals

A uniform mixture of 2 or more substances

Mechanical Mixtures

A mixture where you can see the difference between the types of matter

Chemical Compounds

Molecule

2 or more atoms that are chemically joined in a unit.

Chemical Formula

A notation that indicates the type and number of atoms in pure substances

How Atoms Combine

Elements combine to become more stable and fill their shells

Metals form mixtures with other metals (alloys)

Metals bond with non-metals to form compounds (ionic)

Non-metals bond with non-metals to hold atoms together (covalent bond)

Biology

Understanding Ecosystems

Spheres

Atmosphere

The layer of gases surrounding Earth

Lithosphere

Earth's solid outer layer

Hydrosphere

Earth's water in its 3 forms

Biosphere

Zone where life can exist on Earth

Ecosystems

All living organisms and their physical and chemical environment

Factors

Biotic

Living things and their remains and features associated with their activities

Abiotic

Non-living physical and chemical factors of an ecosystem

Sustanibility

The ability to maintain an ecological balance

Sustainable Ecosystem

An ecosystem that is maintained through natural processes

Energy flow

Types of energy

Radiant energy

Energy that travels through empty space

Light energy

Radiant energy that is visible to the human eye

Thermal energy

Energy transferred during heating or cooling

Cycles

The carbon cycle

The biogeochemical cycle in which carbon is cycled within the 4 spheres.

Photosynthesis

The process in which the sun's energy is converted into chemical energy

carbon dioxide + water = sugar + oxygen

Cellular respiration

The process in which chemical energy is converted into useable energy

sugar + oxygen = carbon dioxide + water + energy

Food Chains and Food Webs

Food chains

A sequence of organisms each feeding on the next

Food webs

A representation of the feeding relationships within a community

Ecological niche

The function a species serves in an ecosystem

Trophic levels

First Trophic Level

Producers

An organism that goes through photosynthesis

Second Trophic Level

Primary Consumers/Herbivores

Organisms that only consume plants

Third Trophic Level

Secondary Consumers/Carnivores

Organisms that only consume other animals

Fourth Trophic Level

Tertiary Consumers/Omnivores

Organisms that consume both plants and animals

The Water Cycle

The series of processes in which water cycles through the environment

The Nitrogen Cycle

The series of processes in which nitrogen compounds are moved through the biotic and abiotic environment

Biotic and Abiotic Influences

Carrying Capacity

The maximum population size of a particular species in a sustainable ecosystem

Tolerance Range

The abiotic factors in which a species can survive

Limiting Factors

Any biotic or abiotic factor that restricts the size of a population

Natural Ecosystems and Stewardship

The Importance of Biodiversity

Biodiversity is important because species are dying out or going extinct in an unnatural way affected by human activity. Biodiversity ensures that we have a more diverse food web in which the negative impact of one species doesn't effect the entire ecosystem as much.

Biodiversity

The variety of life in a particular ecosystem

Habitat Loss

Is one of the most serious threats to Earth's ecosystem

Fragmentation

Reduces ecosystem's sustainability

Is the dividing up of a region into smaller fragments

Native Species

Organisms that originated in a specific area

Non-Native Species

Organisms that came in from another area

Non-native species are a concern because you don't know how they will react or take over with a native species and can disrupt the entire food web.

Ecosystems by Design

Pesticides

Pesticides have benefits such as more food and better health

Pesticides have a big environmental cost

Managing soil

Use natural and synthetic fertilizers

Natural fertilizers may not have as many benefits with growing crops, but have less environmental cost

Synthetic fertilizers have more benefits with growing crops, but also have more environmental cost

Bioaccumulation

The concentration of a substance in the body of an organism

Bioamplification

The increase in concentration of a substance as it moves through the food web

Space

Astronomy

The scientific study of what is beyond Earth

Celestial object

An object that exists in space

Universe

Everything that exists

The Origin and Evolution

The universe is always expanding

The Big Bang Theory

The theory that the universe began in an incredibly hot, dense expansion, approximately 13. 7 billion years ago

Stars

A massive collection of gases held together by its own gravity and emitting huge amounts of energy

Luminosity

The total amount of energy produced by a star per second

Magnitude

Apparent Magnitude

The brightness of stars in the night sky as they appear from Earth

Absolute Magnitude

The brightness of stars as if they were located 33 ly from Earth

Star Colour

Solar Mass

A value used to describe the mass of stars and galaxies other than the sun (2 x 10^30 kg)

Life Cycle of Stars

Nebula

A massive cloud of interstellar gas and dust (beginning of the star)

Protostar

A massive concentration of gas and dust that is thought to eventually become a star after the nebula collapses

Star

Nuclear fusion helps turn the core of a protostar into a star

Supernova

The death of a star as it burns out

Hertzsprung-Russell Diagram

Planets

A large round celestial object that travels around the star

Satellites

A celestial object that travels around a planet or dwarf planet

Galaxies

A huge rotating collection of gas, dust, and other celestial objects

Sun

Electromagnetic Radiation

Energy emitted from matter that travels at the speed of light

The Structure of the Sun

Solar Flare

Gases and charged particles expelled above an active sunspot

Sunspots

Dark spots appearing on the sun's surface that are cooler than the area surrounding them

Solar System

The sun and all the objects that travel around it

Astronomical Unit

Approximately 150 million km

The Solar Nebula Theory

Explains that the solar system was formed around 5 billion years ago from a massive cloud of gas and dust (the solar nebula) that began to contract

Asteroids

Small celestial objects composed of rock and metal

Asteroid Belt

Located between Mars and Jupiter

Motions of Earth, the Moon, and Planets

Earth's Rotation

Takes 24 hours to complete 1 rotation around Earth's axis

Earth's Revolution

Motion of the Moon

Rotates around it's axis and revolves around the Earth, in the same time

Gravity

Gravitational Force

The force of attraction between all masses in the universe

Earth's Tilt

23.5 degrees from the vertical

Contributes to different seasons

Phases of the Moon

Patterns in the Night Sky

Constellations

A grouping of starts as observed from Earth

Electricity

Static electricity

The imbalance of electrical charge on the surface of an object

Electric Charge

A positive or negative charge that exerts an electric force

Charged/Neutral Objects

Neutral Objects

An object that has an equal number of protons and electrons

Negatively Charged Objects

An object that has more electrons than protons

Positively Charged Objects

An object that has fewer electrons than protons

Detecting Static Electric Charge

The Electroscope

A pith ball electroscope is a pith ball suspended by a thread and is used to test for the presence and type of electrical charge on an object.

Law of Electric Charges

Objects that have like charges repel each other

Objects that have opposite charges attract each other

Charging

Charging by Friction

When two different neutral materials come in contact and electric charges are transferred

Charging by Conduction

Charging an object by contact with a charged object

Charging by Induction

Charging a neutral object by bringing a charged object close to the original object

Grounding

Connecting an object to a large body that is capable of removing an electric charge

Conductors and Insulators

Conductors

Materials that electrons move easily through it

Insulators

Materials that electrons can't easily move through

Electrical Discharge

The rapid transfer of electrons from one object to another

Current Electricity

The controlled flow of electrons through a conductor

Electric Circuits

A continuous path in which electrons can flow

Parts of a circuit

Load

The part of an electric circuit that converts electrons into other forms of energy

Switch

A device in an electric circuit that controls the flow of electrons by opening or closing the circuit

Electric Cells

A device that converts chemical energy into electrical energy

Types of Cells

Primary Cells

Can only be used once

Secondary Cells

Are re-usable

Series Circuit

A circuit in which the loads are connected end to end

Parallel Circuit

A circuit in which the loads are connected by branches

Forms of Current Electricity

Direct Current

A flow of electrons in one direction in an electric circuit

Alternating Current

A flow of electrons that alternates in direction in an electric circuit

Measuring Current

An ammeter connected in series (amperes)

Measuring Voltage

A voltmeter connected in parallel (volts)

Resistance

The ability of a material to oppose the flow of electric current (ohms)

Measured with an ohmmeter

Ohm's Law

V = I x R

I = V/R

R = V/I