CHAPTER 1 AND 2: FINALS REVIEW Flashcards
from oldest to newest, list the different atomic models
Democritus’ model, Dalton’s atomic model, Thompson’s atomic model (the plum pudding model), Rutherford atomic model, Rutherford-Bohr atomic model, the simplified atomic model
what principles did Dalton’s model consist of?
- All matter is composed of atoms
- all the atoms of one single element are identical
- atoms of differing elements are different
- atoms of different elements can combine in fixed proportions
- nothing is lost nor gained during chemical reactions
What did Thompson discover using cathode rays?
Using cathode rays he deduced that cathode rays are negatively charged (the rays are attracted to the positive pole of an electrical field), contains particles (able to move a propeller, able to cast a shadow) meaning they emit electrons, a particle that can detatch itself from an atom.
what three types of radiation can radioactive substances give off to eachother?
alpha, beta, and gamma rays
What happened during the gold foil experiment? What did it help deduce?
Ernest Rutherford deduced that some alpha particles were deflected and some bounced back (small, dense, positively charged nucleus), and many passed through (an atom is mostly empty space)
What did the Rutherford-Bohr model improve on regarding the atmoc model?
Through finding out that electrons can move to a higher orbit when charged, the model was given orbits
True or False: The simplified atomic model is the only model with neutrons?
True (added by James Chadwick)
Why were neutrons added?
If neutrons didn’t exist, nuclei would explode when being all positive
when talking about atomic mass and atomic numbers, what does z and a represent
Z- atomic number
A- atomic mass
What differes different isotopes?
Different number of neutrons
what three types of isotopes are there?
Natural isotopes - found in nature
Artificial isotopes - manufactured by bombarding atoms with other atoms
Radioactive istopes - break down radiactively, releasing radiation
How do you calculate an element’s relative atomic mass?
((relative abundance of isotope 1 x atomic mass) + ( “ “+…)/100
What are the 8 groups of the periodic table? what are their characteristics?
Group 1 (alkali metals): soft, light, highly reactive, paired with halogens to form salts, low melting points Group 2 (alkaline earth metals): hard, malleable, grey, found with rocks or with halogens Group 3 (Boron group): loses 3 electrons Group 4 (Carbon group): loses or gains 4 electrons Group 5(Nitrogen group): gains 3 electrons Group 6(Oxygen group): gains 2 electrons Group 7(halogen group): toxic, corrosive, bactericidal, colourful, reacts with H to form acids Group 8 (Noble gases): Colourless, stable, emit light when electrified, found in their elemental states
Name all trends of the periodic table. how to they increase and decrease?
Atomic radius - bigger on the left, smaller on the right. Caused by higher numbers of protons being attracted to the electrons on the atom’s orbits
Ionization energy: energy required to steal a valence electron from an atom. less of this on the right, more on the left. Increases going up
Electronegativity: energy an atom has to remove a valence electron. less on the right, more on the left. Increases going up
Chemical reactivity: how vigourously and atom will recat with others. More reactive on the left, less on the right
What is Avogadro’s number
6.023 x 10 to the power of 23
What is molar mass?
mass of a mol from a given substance measured in g/mol
What is the formula for finding molar mass
M=m/n (m being mass in g, n being number of moles)
What is the formula for finding the number of particles?
n= # of particles/avogardro’s #
What is a molecule
prticle formed by the combination of two or more elements
What is a compund
Pure substance formed by the combination of two or more elements
What’s an ion?
Atoms thats have lost or gained electrons
Polyatomic ions are ions made of several atoms. What are the most common ones?
Acetate, ammonium, ammonia, bicarbonate, carbonate, chlorate, chromate, hydroxide, nitrate, nitrite, phosphate, sulphate, sulphite
What is the difference between ionic bonds and covalent bonds
Ioinic: Bond between metal and non-metal. A metal will transfer the electrons
Covalent: Bond between two non-metals. the atoms will share the electrons
What are the diatomic elements?
Hydrogen, nitogen, flourine, oxygen, iodine, chlorine, bromine (Have no fear of ice cold beer)
What are the prefixes for covalent bonds?
1 Mono 2 di 3 tri 4 tetra 5 penta 6 hexa 7 hepta 8 octa 9 nona 10 deca finish the last element with "ide", dont use mono for the first element if suffix is 1
How do you name ionic bonds
- +ve ion first
2.use ide for negative ion
Mention number of valence electrons for transition metals (e.g., Iron (III) phosphate)
**Use crossover rule to go from name to formula
what is an aqueous solution?
a solution in which the solvent is water
what is a solution
a homogenous mixture where components cannot be distinguished no matter what
How can we find concentration in g/L
C= m/v (mass, volume)
How can we find concentration in mol/L
C=n/v (mol, volume)
How can we find concentration percentage in g/mL
C= m1/m2 x100%
How can we find concentration percentage in mL/mL
C= v1/v2 x100%
How can we find concentration in ppm?
Cppm= mg/kg
How do we calculate dilution?
C1V1=C2V2
What is an electrolytic solution?
Solution with electrolytes
What is electrolytic dissociation? How does it differ from molecular dissociation?
When electrolytes (substances that allow electricity to flow when sperated in a solution) seperate into cations and anions vs. When nonelectrolytes seperate and dont produce ions and do not conduct electricity
what does the conductivity of a solution depend on?
of ions, mobility, changes in direction
What are the three types of electrolytes?
Acids, bases, salts
What determines an acid
The presence of H+ at the beginning (exlcuding acetic acid, an organic acid)
What determines a base?
The presence oh OH- (excluding ammonia due to how it transforms into ammonium and hydroxide when dissolved in water)
how do you name an acid
hyrdro+nonmetal+ic acid
how do you name a base
Metal hydroxide
What determines a salt?
bonding of a metallic and nonmetallic ion excluding OH- and H+
True or False: all salts are neutral
False. some salts are more acidic and others are more basic
Name two alcohols
Ethanol C(2)H(5)OH- Methanol CH(3)OH- false bases
Looking at the pH scale, what signifies if something is neutral and acid or a base
Acid - below 7
neutral - 7
basic- above 7
What does the pH scale being logarithmic mean?
difference of one unit between two substances = one substance is 10x more acidic or basic than the other
what is pOH? what is a pH
- potential of hydroxide
2. potential of hydrodgen
How do you calculate pH? how do you calculate pOH?
pH = -log(H+) pH+pOH = 14
how do you determine the concentration of hydrogen? what about concentration of hydroxide?
(H+) = 10(thpwr of -pH) (H+)(OH-) = 1x10(thpwr of -14)
