Chemistry Regents Review

Flashcards from Chemistry Regents Review Notes

Protons

Have a +1 charge.

Neutrons

Have a 0 charge.

Atomic Mass Unit (amu)

The mass of a neutron = 1 amu = the mass of a proton

Electrons

Have a charge of -1 and a mass of 0.

Location of Protons and Neutrons

Located in the nucleus of an atom.

Charge of an atom’s nucleus

Equal to the (+) number of protons

Mass number

Number of protons + number of neutrons

Atomic number

Number of protons (All atoms of the same element have the same atomic number)

Isotopes

Atoms with the same number of protons, different number of neutrons (different mass number)

Atomic mass

Weighted average of all the naturally occurring isotopes for that element

Rutherford’s Gold Foil Experiment

Shows an atom is mostly empty space with a small, dense, positively charged nucleus.

Wave-mechanical model (electron cloud model)

An orbital (cloud) is the most probable location of electrons

Neutral Atom

Has the same number of protons and electrons as long as there is no charge (total charge of 0)

Ion

A charged element (it has lost or gained electrons): electron configuration will change if it is an ion (possible charges are found on PT)

Electron configuration

Shows location of electron in their shells.

Valence electrons

Electrons found in the outer most shell (last number in electron configuration)

Excited electron

At higher energy level moves to ground state (lower energy level), a specific amount of energy is emitted (sometimes as light/bright line spectrum)

Transmutations

Describes all nuclear reactions (examples: fission, fusion, decays)

Fusion

Light nuclei combine to form a heavy nucleus and a lot of energy

Half life

Length of time it takes for ½ mass of a sample to decay

Substance

Compound or element

Element

Cannot be broken down by chemical means (it is an element if it is on the Periodic table/Table T)

Homogeneous mixtures (solutions)

Even distribution of particles (aq-­dissolved in water) substance has to be soluble to mix with water

Heterogeneous mixtures

Not even throughout. Contains a substance that will not be soluble in water.

Chemical property

How substances react

Chemical change

Results in the formation of a difference substance (example: burning)

Physical change

Do not form new compounds, commonly phase changes (change in distance between molecules)

Solids

Atoms are close together

Liquids

Atoms are in the middle

Gases

Atoms are far apart

Deposition

Gas to solid phase change

Sublimation

Solid to Gas phase change

Density

mass/volume (g/ L or g/cm3)

Thermal energy (heat)

Measured in joules (J) = random motion of atoms and molecules

Average kinetic energy

Temperature

Heat of vaporization

Amount of heat required to vaporize a substance (table B for water constants) = 2260J or 2.26 x 10^3 J

Heat of fusion

Heat it takes to melt a substance. Less than heat of vaporization because it requires less heat to melt a substance than boil a substance.

Exothermic

Energy exits (is released)

Endothermic

Energy absorbed (heat is shown on left side of equation)

STP (Standard Temperature and Pressure)

273 K and 1 atm or 101.3 kPa and 0C (on Table A)

Conditions for ideal gas

PLIGHT: pressure low ideal gas high temperature

Metals

(Left of the staircase) are good conductors of heat, malleable

Nonmetals

To the right of the staircase

Metalloids

On the staircase

Noble gases

(Group 18) are stable because of their stable electron configuration (8 valence electrons), they are not reactive

MELPS

Metals Electrons Lost form Positive Smaller ions

Electronegativity

Attraction for electrons in a chemical bond

BARF

Bond BROKEN energy ABSORBED (endothermic), energy RELEASED bond FORMED (exothermic)

Covalent bond

Nonmetals (molecular compound)

SNAP

Symmetrical nonpolar, asymmetrical polar (molecule polarity)

Intermolecular forces (IMF)

Stronger IMF = High boiling point

Gram formula mass (GFM)

Found by getting the mass of each element (multiplied by their subscript if they have one) and add all masses together

Empirical formula

Simplified formula, molecular is normal not simplified formula

Electrolytes

Acids, bases, salts

Arrhenius theory

Acids yield H+ ion and bases have an OH-

BAAD

BASES ACCEPT H+ ACIDS DONATE H+

Neutralization

Acid + base --> salt + water

Indicators

Range on the reference table (table M) is when the color is in-between two primary colors

Oxidation

Electrons are lost (electrons on right)

Reduction

Electrons are gained (electron on left)

AN OX RED CAT

Anode oxidation, reduction cathode

Voltaic cell

Chemical energy is converted to electrical energy spontaneously

Electrolytic cell

Electrical energy to chemical energy

Saturated hydrocarbons

Have all single bonds (2 electrons shared)

Unsaturated compounds

Have double or triple bonds between carbons

Isomers

Same number of C’s and H’s but are in a different structural arrangement (same molecular formula)