Co Sci Semester 2 Exam

Kinetic theory

Says that all matter is composed of tiny particles, they are always in motion, collide tihw each other/their containeer, and the amountof energy lost from them is very little

Melting point

The temperature at which a solid becomes a liquid

Heat of fusion

the energy required to change a substance from solid to liquid at its melting point

Boiling point

The temperature at which a liquid changes to a gas

heat of vaporization

The amount of energy required for the liquid at its boiling point to become a gas

Sublimation

A change directly from the solid to the gaseous state without becoming liquid

Plasma

a state of matter in which atoms have been stripped of their electrons and can overcome forces between particles

Thermal expansion

an increase in the size of a substance in response to an increase in the temperature of the substance

Thermal energy

The total energy of motion in the particles of a substance

Temperature

the average kinetic energy of particles in a substance

Spreads out

What does water do in response do being cooled (opposite of other substances)

Buoyancy

The ability of a fluid to exert an upward force on an object placed in it (ability to float)

Archimedes Principle

the principle that states that the buoyant force equals the weight of the fluid that the object displaces

Pressure

the amount of force exerted per unit area of a surface

Pascal's principle

Pressure applied to n e area id transferred to the rest of the fluid

Bernoulli's Principle

as the velocity of a fluid increases, the pressure exerted by the fluid decreases

Viscosity

A liquid's resistance to flowing

Decreases

As volume increases, density.....

Boyle's Law

States that there is an inverse relationship between pressure and volume

Charles law

States that there is a direct relationship between volume and temperature

Gay-Lussac's Law

States that there is a direct relationship between pressure and temperature

Substance

Matter that has a fixed Compostion

Element

matter made up of only one kind of atom

Compound

A substance made up of atoms of two or more different elements joined by chemical bonds

Tyndall effect

Scattering of a light beam as it passes through a colloid

homogenous mixture (solution)

a mixture in which the composition is uniform throughout (one phase)

Heterogenous mixture

A mixture in which substances are not evenly mixed (two phase)

Suspension

particles in a solvent are so large that they settle out unless the mixture is constantly stirred or agitated

Colloid

A mixture containing small, undissolved particles that do not settle out.

Mixture

A combination of two or more substances that are not chemically combined

Physical properties

A characteristic of a pure substance that can be observed without changing it into another substance

Chemical properties

Can be observed when matter changes into something else

Physical changes

Any change that DOES NOT alter the chemical composition of a substance.

Chemical changes

A change in which one or more substances combine or break apart to form new substances.

Law of conservation of mass

Matter is not created nor destroyed in any chemical or physical change

Distillation

a liquid is boiled to produce a vapor that is then condensed into a liquid

Atom

Smallest piece of matter that retains the element's properties

Nucleus

Contains the most mass of the atom

Quarks

Three smaller particles that make up protons and neutrons

Dalton Model

solid sphere of an atom

Plum Pudding Model

JJ Thomas and Kelvin's model with electrons ingrained in a positive atom (Cathode Ray Experiment)

Nuclear Model

Rutherford's model that consisted of a nucleus with electrons surrounding it (Gold Foil experiment)

Planetary Model

Bohr's model that had electron shells/energy levels and a nucleus

Quantum Mechanical Model

Schrödinger's model that had an electron cloud and nucleus

Mass number

sum of protons and neutrons

Atomic number

the number of protons in the nucleus of an atom

Average atomic mass

the weighted average of the atomic masses of the naturally occurring isotopes of an element

Isotopes

Atoms of the same element that have different numbers of neutrons

Periods

Horizontal rows on the periodic table

Groups

Vertical columns on the periodic table

Electron Dot Structure

a notation that depicts valence electrons as dots around the atomic symbol of the element; the symbol represents the inner electrons and atomic nucleus; also called Lewis dot structure

Periodic table

the elements are arranged by increasing atomic number and by changes in physical and chemical properties (Moseley)

Chemical formula

shows the elements in the compound and the ratio of atoms

Chemical bond

the force that holds two atoms together

lose

Metals \_______ electrons.

Gain

nonmetals \____ electrons

Ion

A charged particle that either has more or fewer electrons than protons

Ionic bond

Formed when one or more electrons are transferred from one atom to another

Covalent bond

A chemical bond formed when two atoms share electrons

Molecule

two or more atoms held together by covalent bonds

Formula unit

Atoms held together in an ionic bond

polar covalent bond

A covalent bond in which electrons are not shared equally

Nonpolar covalent bond

a covalent bond in which the electrons are shared equally by the two atoms

Nonpolar molecule

a molecule that does not have oppositely charged ends

Polar molecule

molecule with an unequal distribution of charge, resulting in the molecule having a positive end and a negative end

Oxidation number

Positive or negative number that indicates how many electrons an atom has gained, lost, or shared to become stable

Polyatomic ions

A charged group of covalently bonded atoms that have an overall charge

Binary compounds

compounds composed of two elements

Hydrate

A compound that has a specific number of water molecules bound to its atoms

Chemical reaction

A change in which one ore more substances are converted into new substances

Chemical equation

a way to describe a chemical reaction using chemical formulas and other symbols

Coefficients

numbers that represent the number of units of each substance taking part in a reaction

Balanced chemical equation

has the same number of atoms of each element on both sides of the equation

Mole

the SI base unit used to measure the amount of a substance (6.01x10^23)

Molar mass

the mass in grams of one mole of a substance

Synthesis reaction

a reaction in which two or more substances combine to form a new compound

Decomposition

A chemical reaction that breaks down compounds into simpler products.

Single displacement

one element trades places with another element in a compound: A + BC --\> AC + B

Double displacement

Both compounds switch metals

Combustion

the process of burning something; produces carbon dioxide and water

Precipitate

an insoluble compound that comes out of solution during a double displacement reaction

Oxidation

loss of electrons

Reduction

gain of electrons

Endothermic

Instant cold packs and cooking are...

Exothermic

Instant heat packs and burning are...

Reaction rate

the rate at which reactants change into products over time

Collision model

states that atoms, ions, and molecules must collide in order to react

Catalyst

Speeds up rate without permanently changing itself

Inhibitors

used to slow down a chemical reaction

Reversible reaction

can occur in both the forward and reverse directions

Equilibrium

A state in which forward and reverse reactions proceed at an equal rate

Le chatelier's principle

Says that if stress is applied to a system as equilibrium, then it shifts int eh direction that opposes the stress

Solute

A substance that is dissolved in a solution.

Solvent

does the dissolving

Alloys

mixtures of two or more metals

Concentration

The amount of solute actually dissolved in a given amount of solvent

Solubility

The maximum amount of how much solute can dissolve in a given solvent at a given temperature

Saturated solution

a solution that cannot dissolve any more solute under the given conditions

Unsaturated solution

any solution that can dissolve more solute at a given temperature

Supersaturated solution

contains more dissolved solute than a saturated solution at the same temperature