Chemistry Semester 1 Final

What are extensive properties?

Properties that depend on the amount of matter that is present

What are signs of a chemical reaction?

Change in color, odor, or temperature; or production of light, precipitate, or gas

What are quantitative observations?

Observations that deal with numbers

What are qualitative observations?

Observations that are descriptive

What is mass?

The amount of matter in an object

Density formula:

Density = mass/volume

What are significant figures?

The valid digits in a measurement

What is Dalton's atomic theory?

1. Matter is composed of small particles called atoms
2. An atom cannot be created, destroyed, divided, or changed
3. Atoms of the same element are identical
4. Atoms of different elements have different properties
5. Atoms of different elements combine in whole number ratios to form compounds.
6. In a chemical change, atoms are rearranged, joined or separated.

Where does the radius of an atom extend to?

The outer edge of the region occupied by electrons

What is Avogadro's number?

6.02 x 10^23

What is the energy of a photon related to?

Its frequency

What shape are s orbitals?

Spherical

What shape are p orbitals?

Dumbbell

What shape are d orbitals?

Clover

What shape are f orbitals?

funky

What is the Aufbau principle?

Electrons occupy the orbitals of lowest energy first

What are elements with atomic numbers from 58 - 71 called?

Lanthanides

What are the properties of alkaline metals?

Soft, shiny, good conductors, low melting points.

What group are the alkali metals?

Group 1

What are the properties of alkaline earth metals?

Harder, denser, stronger than alkali metals, higher melting points, not as reactive.

What group are alkali earth metals?

Group 2

What are the properties of halogens?

Very reactive, form compounds with most elements

What group are the halogens in?

Group 17

What are the properties of noble gases?

Odorless, colorless, low reactivity

What group are the noble gases?

Group 18

What is electronegativity?

The ability of an atom to attract electrons

What is ionization energy?

The energy required to remove an electron from an atom

What is electron configuration?

The arrangement of electrons in an atom

What is electron affinity?

The energy change that occurs when an electron is acquired by a neutral atom

What are the rules of significant figures?

1. All nonzero numbers are significant
2. All zeros that are in between nonzero numbers are significant
3. All zeroes after a nonzero number are significant as long as there is a decimal point
4. All zeros before a nonzero number are not significant

What is an isotope?

Atoms of the same element that have different numbers of neutrons

What is radioactive decay?

The process of unstable atoms changing into smaller more stable atoms

What are alpha particles?

2 protons and 2 neutrons; a Helium nucleus

What are beta particles?

Electrons

What are positrons?

Positively charged electrons

What are gamma rays?

Electromagnetic radiation; high energy, no mass, no charge

What is nuclear fission?

The splitting of a nucleus into smaller fragments

What is nuclear fusion?

The process of combining lightweight nuclei to make heavier nuclei

What are wavelengths?

The distance between crests of waves

What is frequency?

The number of waves that pass a given point per second

What is the equation for the speed of light?

c = λνc = wavelength x frequency

Who is John Dalton?

Father of atomic theory

Who is J.J. Thomson?

He discovered the electron using the cathode ray tube

What is the plum pudding model?

It states that atoms are a ball of positive charge, with negative electrons embedded in it

Who is Robert Millikan?

Calculated the charge of electrons

Who is Ernest Rutherford?

Discovered the nucleus through the gold foil experiment

What is Rutherford's atomic model?

Concluded that atoms are mostly negative space with a positive nucleus and negative electrons surrounding it

Who is James Chadwick?

Discovered the neutron

Who is Niels Bohr?

Created the planetary model of the atom

What are orbitals?

Energy levels where electrons are found

What is the sequence of electron configuration?

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p

What are the properties of metals?

Luster, malleability, ductility, high conductivity, high melting points

What are the properties of nonmetals?

Dull, brittle, low conductors, low melting points

Parts of quantum numbers:

Principal Quantum Number, angular momentum, magnetic, magnetic spin

How is angular momentum written?

Written as 'l'; between 0 - 3

s = 0

p = 1

d = 2

f = 3

How is the principal quantum number symbolized?

Written as 'n'; 'n' = the energy level

What is the magnetic?

Written as '-l, 0, l'

How is the magnetic spin written?

+1/2 for up, -1/2 for down

What is the octet rule?

Atoms gain, lose or share electrons to have a full valence shell

What is the trend for ionization energy?

Increases up and to the right

What is bond length?

The distance between the nuclei of two bonded atoms

What does the chemical formula for an ionic compound show?

The ratio of all the ions present

What is the trend for atomic radius.

It decreases across a period and increases down a group.

What is an empirical formula?

The simplest whole number ratio of atoms of each element in a compound

What is an aqueous solution?

A solution in which water is the solvent

What is a single replacement reaction?

A chemical change in which one element replaces a second element in a compound

What are the requirements for a single replacement reaction?

The compound must be aqueous, and the cation of the element must be higher on the activity series than the cation of the compound

What is a double replacement reaction?

A chemical change involving an exchange of positive ions between two aqueous ionic compounds

What are the requirements for a double replacement reaction?

Both reactants must be aqueous, and one product must be a solid

What is a decomposition reaction?

A reaction in which a compound breaks down into two or more simpler substances

What is a combustion reaction?

A reaction in which a substance reacts with oxygen and releases energy

What is a combination/synthesis reaction?

A reaction in which two or more substances form a single new substance

What is an activity series?

A list of elements organized according to the ease with which the elements undergo certain chemical reactions

What kind of bonds to molecular substances have?

Polar covalent bonds

When is a line spectrum produced?

When an electron moves to a lower energy level

What are dipole-dipole forces?

Attractions between oppositely charged regions of polar molecules

What are London dispersion forces?

The temporary attraction between electrons of atoms caused by dipoles

What are the properties of molecular compounds?

Lower melting points and no conductivity

What are the properties of ionic compounds?

High melting points and high conductivity

What is the Pauli Exclusion Principle?

No two electrons in the same atom can have the same set of four quantum numbers

What is the periodic law?

The physical and chemical properties of the elements are periodic functions of their atomic numbers

What is a row on the periodic table called?

Period

What is a column on the periodic table called?

Group

What do alkali metals occur as in nature?

Compounds

What is the central atom in a Lewis Dot Structure?

The least electro negative atom

What is the VESPR theory?

The electron geometry of a molecule is determined by the number of groups of electrons around the central atom

What is the electron sea model?

The model of metallic bonding where electrons float free in a sea of electrons around metal atoms.

What are the steps to convert percent compositions into empirical formulas?

Multiply the percentages (as a decimal) by the weight of one of their respective atoms, then divide each number by the smallest product

What is a net ionic equation?

An equation that shows only those particles involved in the reaction, and that is balanced for both mass and charge

What is ionic character?

The difference in electronegativity

What is a London force?

An induced dipole-dipole attraction

What is Hund's rule?

Electrons will fill an unoccupied orbital before they pair up

What is a pure substance?

A substance in which there is only one type of element or compound

What is a mixture?

A substance in which there are multiple types of elements and/or compounds

What is a homogeneous mixture?

A mixture where the substances are evenly blended together

What is a heterogeneous mixture?

A mixture that is not blended evenly

What is the law of conservation of mass?

Matter cannot be created or destroyed in a chemical reaction

What is lattice energy?

The energy required to separate 1 mole of the ions in an ionic compound

What is the electron sea model?

The model of metallic bonding where electrons float free in a sea of electrons around metal atoms.

What is an electron group?

Bonded or lone pairs of electrons in the central atom