APES CHAPTER 2

Matter

Anything that occupies space and has mass

Mass

A measurement of the amount of matter an object contains

Atom

The smallest particle that can contain the chemical properties of an element

Element

A substance composed of atoms that CANNOT be broken down into smaller, simpilar components

Structure of atom

protons, neutrons, electrons

Nucleus

the center of an atom, which contains the positively charged protons and neutrons

Negatively charged electrons

orbit the nucleus

Periodic table

a chart of all chemical elements currently known, organized by properties

Molecule

a particle that contains more than one atom

compound

a molecule containing moe than one element

atomic number

number of protons in the nucleus of a particular element

mass number

measurement of the total number of protons and neutrons in an element

Radioactive decay

the spontaneous release of material from the nucleus of radioactive isotopes

What is an isotope?

An atom of a specific element that has the same number of protons but a different number of neutrons compared to other atoms of the same element.

What do isotopes of an element have in common?

They have the same number of protons.

What differs among isotopes of the same element?

The number of neutrons.

half-life

the time is takes for one half of an original radioactive parent atom to decay

covalent bond

bond formed when elements share electrons

chemical bonds

covalent, ionic, hydrogen

ionic bonds

a chemical bond between 2 ions of opposite charges

What is a hydrogen bond?

A weak chemical bond.

When do hydrogen bonds form?

When hydrogen atoms are covalently bonded to one atom and are attracted to another atom on another molecule.

Polar molecule

a molecule in which one side is more + and the other side is more -

What is surface tension?

A property of water that results from the cohesion of water molecules at the surface.

What creates a sort of skin on the surface of water?

Surface tension.

capillary action

a property of water that occurs when adhesion of water molecules to a surface is stronger than cohesion between the molecules

Water boils at

100 C

Water freezes at

0 C

Acid

a substance that contributes hydrogen ions to a solution

Base

A substance that contributes hydroxide ions to a solution

pH

the number that indicates the relative strength of acids and bases in a substance

ocean acidification

an increase in the acidity of the oceans

pH of 7

neutral

pH above 7

basic

pH under 7

acidic

Chemical reaction

a reaction that occurs when atoms separate from molecules or recombine with other molecules

Law of conservation of matter

Matter is not created nor destroyed

inorganic compound

a compound that does not contain the element carbon or contains carbon bound to elements other than hydrogen

Organic compound

A compound that contains carbon-carbon and carbon-hydrogen bonds

Carbohydrate

A compound composed of carbon, hydrogen and oxygen atoms

What is a critical component of living organisms?

Protein

What are proteins made up of?

A long chain of nitrogen-containing organic molecules known as amino acids

Nucleic acid

organic compounds found in all living cells

What is DNA?

A nucleic acid.

What does DNA contain?

The genetic material that contains the code for reproducing the components of the next generation.

What do organisms pass on to their offspring?

DNA.

What is RNA?

A nucleic acid.

What is the function of RNA?

Translates the code stored in DNA.

What does RNA synthesis make possible?

The synthesis of proteins.

Lipid

A smaller organic biological molecule that does not mix with water

What is a cell?

A highly organized living entity.

What are the four types of macromolecules found in a cell?

Proteins, nucleic acids, carbohydrates, and lipids.

What surrounds a cell?

A membrane.

Energy

The ability to do work or transfer heat.

Joule

The amount of energy used when a 1-watt electrical device is turned on for 1 second.

Power

The rate at which work is done.

Energy conversion

power x time

Electromagnetic radiation

A form of energy emitted by the Sun that includes, but is not limited to, visible light, ultraviolet light, and infrared energy.

Photon

A massless packet of energy that carries electromagnetic radiation at the speed of light.

potential energy

Stored energy that has not been released.

Chemical energy

Potential energy stored in chemical bonds.

Kinetic energy

the energy of motion

Temperature

The measure of the average kinetic energy of a substance.

First law of thermodynamics

A physical law which states that energy can neither be created nor destroyed but can change from one form to another.

First law of thermodynamics

The physical law stating that when energy is transformed, the quantity of energy remains the same, but its ability to do work diminishes.

Energy efficiency

The ratio of the amount of energy expended in the form you want to the total amount of energy that is introduced into the system.

Energy quality

The ease with which an energy source can be used for work.

Entropy

Randomness in a system

Randomness

always increasing in a system, unless new energy from outside the system is added to create order.

Open system

A system in which exchanges of matter or energy occur across system boundaries.

Closed system

A system in which matter and energy exchanges do not occur across boundaries.

input

addition to a system

Output

loss from a system

systems analysis

An analysis to determine inputs, outputs, and changes in a system under various conditions

Steady state

A state in which inputs equal outputs, so that the system is not changing over time.

Negative feedback loop

A feedback loop in which a system responds to a change by returning to its original state, or by decreasing the rate at which the change is occurring.

Positive feedback loop

a feedback loop in which change in a system is amplified