chemistry CLEP

precision

How close the values are to each other

Accuracy

How close the values are to the goal

Significant figures

Tell scientists how accurate your data was. Adding a point at the end of 450. tells scientists that your measurements are down to the liter.

Ionic substances nomenclature

Generally have no prefixes but still have ide at the end (Sodium Chloride)

Covalent compound nomenclature

Have the prefixes mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca

Inorganic compound

A compound that does not have both carbon and hydrogen

Organic compound

Compound with both Hydrogen and Carbon in it

Ionic compounds

When a metal and a nonmetal give each other electrons creating an ionic bond

Hydrates

Compounds with water in there formula

A hydrates

Compounds without water

Sub-atomic-particles

Protons, neutrons, electrons

JJ Tomson

Pioneered the Atomic Theory, Millikan oil drop experiment, the gold foil experiment

Isotopes

The same element with a different number of neutrons

Nucleon

Molecule that lives in the nucleus (protons, neutrons)

amu

Weight unit of atoms. Equals one 12th the weight of carbon 12.

amu equation

Number of element times its abundance plus all the other kinds of elements. 12(.988) + 13(.011) + 14(.001) =12.013 amu for carbon

Spectrophotometer

A tool for measuring the abundance of an isotope in a sample

fission

Splitting of a heavy element into different smaller elements by shooting a neutron at it.

Fusion

Joining lighter nucleus into heavier ones

A decay

Loss of helium in a element

B decay/ B minus decay

Loss of electron in medium sized elements through splitting a neutron

neutron

a proton and electron stuck together

B plus decay

Loss of a positron

Positron

Same as an electron but has a positive charge

Electron capture

Gain of electron, opposite to B minus decay

Metastable

When a structure or system (like an atom) is in a state to where it is stuck in a localized minimum and would need a small amount of outside energy to react and drop to its true lowest energy state.

The difference between nuclear reactions and chemical reactions

Nuclear reactions happen at the nucleus levels while chemical reactions happen at the electron level

What does a higher frequency of light equate to

Higher energy

Describe the Electromagnetic spectrum

A table showing the lowest wavelength of light/ lowest energy (left side), to the highest wavelength of light/ highest energy (right side), with a small amount of light in the middle that humans can see.

Spectrophotometry

When scientist “inject” energy into the electrons of an element, those electrons product photons when decreasing in energy, and the difference in the max amount of energy minus the energy level of the electron, when it has returned to its lowest energy state, depending on what shell it is in, helps scientists identify an element. Since each element has a different number of electrons, the amount of photons released from this experiment differ, meaning scientists us spectrophotometry to identify elements.

Planck’s constant

6.626 × 10 ^ -34 Joules per second

Planck’s equation/law

Energy of a photon = Planck’s constant * Frequency

Bohrs model/ discovery

Electrons orbit the nucleus in shells/ levels including sub shells, and emit photons when moving toward the nucleus/ absorb photons when moving to shells further from the nucleus.

Orbitals

Pairs of electrons that rotate in opposite directions in the same shape on the lame level and sub level.

Periods

Starting at the top of the periodic table, periods are horizontal groupings of elements representing what level the valence electrons are located in.

Groups

Starting on the left side of the periodic table, groups are vertical groupings of elements that represent the number of valence electrons an element has.

Alkali metals

The elements in the first group on the periodic table excluding hydrogen.

Characteristics

• have one valence electrons and are keen on give it away to become positive ions

• React violently with other substances like halogens

• Very soft

• Very light and low density (so even float on water)

• Form oxide coating when exposed to oxygen and moist

Alkaline-earth metals

The elements in the second group of the periodic table

Key Characteristics

• They have two valence electrons and are keen on giving away both of them to become stable

• Very reactive but notably less reactive then Alkali metals

• Tougher metals than Alkali metals, but less tough than transition metals

• Have higher melting points than Alkali metals

• When dissolved in water they produce a basic solution rather than an acidic one

Transition metals

Transition metal span from group 4-12

Key characteristics

• Less reactive metals with different number of valence electrons from 4-12. Sometimes deals with sub shells rather than full shells to make them mores stable due to the large number of valence electrons

• Harder and denser than Alkali and Alkaline- earth metals with much higher melting points

• Can be used as Catalysts to speed up reactions

Noble gasses

Located in group 18 of the periodic table

Key characteristics

• remarkable unreactive due to their naturally complete outer shell with no valence electrons

• Won’t find them in almost any compounds as they do not need to

• They are single atoms that you can not see smell or taste

• Are gasses even in some of the most extremely cold temperatures with a boiling points in the extreme negatives

• Reacts highly when electrical current flows through them with colorful lights (that’s why they are used in colorful signs).

Halogens

Exist in group 17 of the periodic table

Key characteristics

• All halogens have 7 valnce electrons and are keen to gain one more to be stable, meaning they are react Violently with Alkali and Alkaline-earth metals

• Halogens showcase all three forms of matter at room temperature depending on the halogen

• Extremely hazardous and dangerous before they gain that extra electron

• In nature halogens form and stay in pair, sharing an electron until a full ionic reaction can take place

Post transition metals/ other metals

Post transition metals are located to the right of transition metals and below the stair case next to the Metalloids

Key characteristics

• Relatively low melting points

• Softer and less dense than transition metals

• Create covalent bonds more readily

• They conduct electricity and heat but are worse at doing so than transition metals and alkali metals

• Tend to be brittle

Reactive nonmetals

To the right of the metalloids and to the left of the halogens including Hydrogen

Key characteristics

• poor conductors

• Varied forms of matter at room temperature

• High electronegativity and tend to share electrons rather than give electrons

• Essential for life with 96 percent of living organisms being made of these

Rare-earth elements

Sitting in the top row of the two detached rows of the periodic table (including the first two elements Scandium and Yttrium of group 3 on the main periodic table portion)

Key characteristics

• Very similar in chemical makeup

• Very abundant in the earths crust but spread out and not concentrated into veins making them expensive to collect

• Elements like neodymium, praseodymium, and dysprosium are essential in many modern day technologies

• In their pure form they react violently with water and are white

Metalloids

Located just on top of the stair case between the metals and nonmetals

Key characteristics

• Are known for being semiconductors because they conduct electricity between when heated

• Look like metal but are brittle

• Can act like metals or nonmetals depending on what they are reacting with

• Are solid at room temperature with relatively high melting and boiling points

S block elements

Located on the left side of the transition metals in the periodic table have valence electrons in the S orbital sub shell

P block elements

To the right of the transition metals have valence electrons in the p orbital

d block elements

Transition metals, have valence electrons in the d orbital

f block

Rare earth metals, bottom strip, have valence electrons in the f orbital

Atomic radius

How far the electrons are from the core. Higher as you go left and down in the periodic table

Ionic radius

The distance the outer most electrons in are in an ion. Metals have smaller ionic radius while nonmetals have larger one generally due to nonmetals gaining an electron and metals losing one. Just depends on the reaction and what elements your working with

Ionization energy

The energy it takes to remove an electron. Ionization energy increases as you go right and up in the periodic table

Electron Affinity

The amount of energy needed to add and electron. Increases as you go right and up

Electronegativity

The tendency of an element to attract an electron closer to itself when forming a covalent bond. Increases as you go right and up in the periodic table

Reduction

Chemical reaction where an electron is gained

Oxidation

Chemical reaction where an electron is loaded

Reducing agent

Substance that causes a reduction

Oxidizing agent

Substance that causes a Oxidation process

Reduction-Oxidation reaction

Reaction where both elements in the reaction experience one

Moles equation

Mass/molar mass

% yield

Actual/ theoretical times 100 percent

Redox reactions

When the reaction that takes place causes oxidation and reduction

Arrhenius theory

States that ions that dissolve in water either make the solution acidic by dissociation of a Hydrogen (H), or basic by the dissociation of Hydroxide (OH)

Electrolytes

Ionic compounds that dissociate in water to leave electricity charges ions freely floating.

Weak electrolytes

Dissolves about 1-10 percent into ions when dissociating in water, and conduct electricity poorly

Strong electrons

Dissociate 100 percent intentions in water, and conduct electricity well

Non- electrons

May dissociate in water but carry zero ionic charge when doing so

Molarity equation

Moles of solute/ liters of solution

Insoluble

If the solubility is less than .01 grams per 100 mL of water at room temperature

Precipitate

The leftover insoluble part of a reaction that is left over after the reaction takes place.

Boyles’s Law

P1V1 = P2V2

Inverse relationship between volume and pressure. As volume increases pressure decreases. As volume decreases pressure increases.

Charles Law

V1/T1 = V2/T2

Direct relationship between temperature and volume. Assuming pressure (in a non rigid/ flexible container) and amount of gas’s stay the same, As you increase temperature, you increase volume. As you decrease temperature, you decrease volume.

Gay-Lussacs law

P1/T2 = P2/T2

Assuming volume (in a rigid container) and amount of gas’s stay the same, As temperature increases pressure increases, and as temperature decreases pressure decreases.

V1/N1