Ev Sci Ch 2

Ev Sci Ch 2

Matter, Energy, and Systems

Open Ended

What is matter?

Open Ended

What is Energy?

Open Ended

What are systems?

What is matter?

• Matter - anything that has mass and takes up space.

• Solid, liquid, gas

• Can be an element or a compound

Elements

• Element - a type of matter with a unique set of properties that cannot be broken down into simpler substances by chemical means.

• Compound -  combinations of two or more different elements held together in fixed proportions

Atoms

• Atom = basic building block of matter

• Smallest unit of matter into which an element can be divided and still have distinct chemical properties

• Can be further broken down into protons and neutrons and electrons.

• Proton - positive charge

• Neutron - no charge

• Electron - negative charge

Atoms

• Atoms can have different mass numbers (varying numbers of nuetrons), creates isotopes

• Isotope - Same atomic number, different mass number

• Most common isotopes of carbon are carbon-12, carbon-13, carbon-14

Molecules

• Molecule - Second building block of matter

• Combination of two or more atoms of same or different elements held together by forces known as chemical bonds

Molecules of life

• Organic compound - carbon-based compound.

• Organic compounds get very complex.

• Include simple carbohydrates that contain C, H, O atoms.

• More complex compounds are polymers

Polymers

• Polymers consist of multiple monomers.

• Glucose is a simple carbohydrate which is a monomer for complex carbohydrates such as starch and cellulose.

• Other types of polymers are proteins, nucleic acids, and lipids.

Nucleic acids and lipids

• Proteins are made of amino acids

• Nucleic acids are made of nucleotides

• Lipids are made of fats

Multiple Choice

What is matter?

• Anything that takes up space and has mass

• Protons, nuetrons, electrons

• The scientific study of life

• Me, I matter.

Multiple Choice

The building block of matter

• Atoms

• Protons

• Electrons

• Nuetrons

Multiple Choice

Atoms are mashed together to form...

• Compounds

• Molecules

• Ions

• Nucleic Acids

Multiple Choice

Organic compounds are ____ based.

• Nitrogen

• Oxygen

• Carbon

• Blood

Multiple Choice

Polymers are made up of multiple _____.

• Ions

• Isotopes

• Protons

• Monomers

Multiple Choice

Nucleic acids are made up of...

• Nucleotides

• Amino Acids

• Ions

• Polymers

Physical and Chemical Changes

• Physical change - no change in chemical composition

• Paper being ripped in half

• H2O melting and freezing

• Chemical change - change in chemical composition.

• Use a chemical equation to show how chemicals are rearranged.

Law of conservation of matter

• Matter is never created nor destroyed

• Matter is only rearranged into different forms

What is energy?

• Energy - Capacity to do work

• Two types of energy

• Potential and kinetic

Kinetic Energy

• Kinetic energy - energy associated with movement.

• Flowing water, speeding car,

• Thermal energy is a form of kinetic energy

• Energy associated with heat

• Heat - Movement of energy

• Temperature - measure of average heat or thermal energy of the atoms, ions, or molecules

• Heat always flows from hot to cold.

Kinetic Energy

• Electromagnetic radiation - Changes in electrical and magnetic fields

• Electromagnetic radiation from the sun is the major source of energy on the earth.

Potential Energy

• Potential energy - stored energy, energy associated with position

• Potential energy can change into kinetic energy.

Energy Quality

• Energy Quality - capacity of energy to do useful work

• High quality - energy that can do useful work

• High temperature thermal energy, high speed wind, energy released by wood, gasoline, natural gas, coal

• Low quality - little capacity to do useful work

• Majority of moving molecules in atmosphere or in the ocean are low quality.

Energy changes are governed by two scientific laws

• First law of thermodynamics - law of conservation of energy

• Second law of thermodynamics - The universe is always proceeding towards a higher state of entropy

• Energy always moves towards a less useful form

System and System Models

• System - set of components that function and interact in some regular way

• Cells, human body, forest, river

• All systems have inputs, throughputs, and outputs of matter

• Affected by feedback

• Matter, energy, or information that, when fed back into the system as input, increases or decreases a change to the system.

• Feedback loop - when an output of matter, energy, or information is fed back into the system as an input and leads to changes in that system.

Positive Feedback loop

• Causes a system to change further in the same direction

• “Snowball effect”

• When a natural system becomes locked into a positive feedback loop, it can reach an ecological tipping point

• Beyond this point, system can change so drastically it could collapse

Negative feedback loops

• Causes system to change in opposite direction

• Thermostat

• Temperature in house increases until it reaches a set temperature, then furnace is shut off.