Chemistry Exam 1

Hydrogen

H

Helium

He

Lithium

Li

Beryllium

Be

Boron

B

Carbon

C

Nitrogen

N

Oxygen

O

Fluorine

F

Neon

Ne

Sodium

Na

Magnesium

Mg

Aluminum

Al

Silicon

Si

Phosphorus

P

Sulfur

S

Chlorine

Cl

Argon

Ar

Potassium

K

Calcium

Ca

Titanium

Ti

Vanadium

V

Chromium

Cr

Manganese

Mn

Iron

Fe

Cobalt

Co

Nickel

Ni

Copper

Cu

Zinc

Zn

Bromine

Br

Krypton

Kr

Rubidium

Rb

Strontium

Sr

Silver

Ag

Cadmium

Cd

Tin

Sn

Iodine

I

Xenon

Xe

Barium

Ba

Gold

Au

Mercury

Hg

Lead

Pb

Radon

Rn

Uranium

U

What makes an atom

protons, neutrons, electrons

Atomic Number

number of protons in the nucleus of an atom

Atomic Mass

the mass of an atom; the number of protons + neutrons in an atom

Molecule

Group of atoms bonded together

Ion

atom or group of atoms, has a net positive or negative charge

Isotope

Atoms with the same number of protons but different numbers of neutrons

Ionic Bond

exchange of an electron that holds atoms together

Covalent

Sharing of electrons

Cation

ion w/ positive charge; Neutral atom loses one or more electrons

Anion

ion w/ a negative charge; Neutral atom gains one or more electrons

Equation for Binding Energy

1. calculate difference in masses between the reactants + products

2. reactants minus products

3. convert from amu to kg (1 amu = 1.66 ×10^-27 kg)

4. Finally convert mass to energy using E=mc²

Alpha Decay

reactant (parent isotope) —> product (daughter) + 4/2 He (alpha expelled)

Beta Decay

1/0 n (in nucleus) —> 1/1 p (in nucleus) + 0/-1 B (Beta expelled)

Positron Emission

1/1 p (in nucleus) —>1/0 n (in nucleus) + 0/1 e (positron expelled)

Electron Capture

0/-1 e + 1/1 p (in nucleus) —→ 1/0 n (in nucleus)

ON REACTANT SIDE

Ionic Compounds

often metal & nonmetal; anion (nonmetal), add -ide to element nature

generally solids

ex: K20: Potassium Oxide

Mg(OH)2: Magnesium Hydroxide

Transition Metal Ionic Compounds

indicate charge with Roman numerals. We don’t know transition charge so we have to indicate it.

ex: FeCl2: Iron (11) Chloride

Cr2S3: Chromium (111) sulfide

Molecular Compounds

• nonmetals or nonmetals & metalloids

• Element furthest left in periodic table is 1st & element closest to the bottom of group is 1st

• If more than one compound can be formed from the same elements, use prefixes to indicate # of each kind of atom

• last element ends in -ide

• generally liquids or solids

Ex: NF3: Nitrogen trifluoride

N2Cl4: dinitrogen tetrachloride

Acid

substance that yields hydrogen ions (H+) when dissolved in water

• ex: Hydrogen chloride—> dissolved in water = hydrochloric acid

Oxoacid

acid that contains hydrogen, oxygen, and another element

• HNO3: nitric acid

• H2CO3: carbonic acid

Base

substance that yields hydroxide ions (OH-) when dissolved in water

• NaOH: sodium hydroxide

• Ba(OH)2: Barium hydroxide

Hydrates

compounds that have a specific number of water molecules attached to water

Avogadro’s Number

units in every mole: 6.022 × 10^ 23 units

Molecular formula

shows the exact # of atoms of each element in the smallest unit of a substance

Empirical Formula

shows the simplest whole number ratio of the atoms in a substance

Solve Stoichiometry + Limiting Reagent Problems

1. need balanced rxns

2. convert given amount to moles

3. use rxn coefficients (molar ratios) to find # moles of wanted stuff

4. convert moles of wanted stuff to grams

5. Find limiting reagent

6. answer other Q’s