FoS - C Final Exam

formula for percent error

|measured - accepted| / accepted x 100 = percent error

why would the graduated cylinder be a better tool to measure 43.8 mL of liquid

the graduations are closer together letting you have a more precise answer. The more graduations, means more significant figures

what does an Erlenmeyer flask look like. Function?

sloped sides. used for holding and mixing liquids

what are significant figures

all the certain digits and one uncertain digit

units and tool to measure mass

grams; electronic balance

units and tools to measure length

feet; ruler

units and tools to measure temperature

degrees C and a thermometer

precise vs accurate

precise is how specific you can make an answer vs accurate is how correct the answer is

Bohr contributions and experiments

emission spectra of various elements to conclude that the electrons go around the nucleus in circular orbits

Rutherford contributions and experiments

shot alpha particles at a gold sheet; concluded that there is a dense positively charged nucleus with empty place

Thomson contributions and experiments

cathode ray; concluded that there is a subatomic particle called the electron

who created the periodic table of elements and how was it organized

Dimitri Mendeleev organized it by atomic mass and common characteristics

group 1

alkali metals

group 2

alkaline earth metals

groups 3-12

transitions

group 17

halogens

group 18

noble gases

same groups have what in common

same \# valence electrons and common characteristics

same periods have in common

valence electrons are on the same principle energy level

3 subatonic particles and their mass, charge, and location

proton- 1.0073 amu; +; nucleus

neutron- 1.0087 amu; 0; nucleus

electron- 5.5 x 10^-4 or 1/2000 of a proton

nuclear notation

mass \# (protons and neutrons)/ atomic \# (protons) then followed by element

difference between isotopes

they have a different number of neutrons. radioactive isotopes have the wrong number of neutrons that make the nucleus unstable

how does an element become stable ( low potenial energy level )

it fulfills the octet rule and fills its outer shell with a full set of valence electrons

covalent compound characteristics

low melting point, poor conductor of electricity

metallic bond characteristics

ductile, good conductor of electricity, malleable

ionic compound characteristics

high melting point, dissolves in water

relationship between the strength of an intermolecular force and it's melting point

high melting point = stronger bond

6 ways to identify a chemical change

gas; color; light; temperature; precipitate; odor

energy released or absorbed when bonds are broken?

absorbed

energy released or absorbed when bonds are formed

released

when the enthalpy of reaction is negative, what type of reaction would it be

exothermic because more energy was released when forming bond than energy absorbed to break the bond

how many electrons are shared in a double bond

4 electrons

molar mass

the mass in grams of 1 mol of a substance

to find the mass of a certain amount of mol of a substance (equation)

amount of mole x molar mass (4.66 mol x 52.03g= 242.46 g/mol)

from mol to particle (equation)

1mole/molar mass x 6.022x10^23 (1 mol/52.03g x 6.022x10^23= g/mol)

Intermolecular vs Intramolecular

intermolecular- between molecules

intramolecular- within the molecules and between atoms

change in energy in photosynthesis

light (sun) \>>> chemical potential energy

change in energy in cellular respiration

chemical potential energy \>>> kinetic, heat, and potential energy

change in energy in combustion of fossil fueled to move a car

chemical potential (fossil fuels)\>>> heat and kinetic energy

fossil fuels vs nuclear power in generating electricity

fossil fuels- combustion; chemical reaction occurs; chemical change; produces greenhouse gases

nuclear power- nuclear fission; radioactive waste; no greenhouse gases; no chemical reaction

what is energy

the ability to do work

Law of Conservation of Energy

Energy cannot be created or destroyed

in photosynthesis what happens to the energy from the sun?

it is used to split the water molecule and stored as chemical potential energy

what are coefficients

numbers infront of the reactants and products used to balance equations. tell us the number of particles of the substance. can be interpreted as moles of particles or \# of particles

difference between chemical and physical change

chemical- in the intramolecular bonds and forms a new product

physical- intermolecular and does not change chemical formula

what type of bond is the strongest (single, double, triple)

triple bonds

why do atoms form bonds

they form bonds to fill their outs shell and have a lower potential energy

which part of the atom participates in chemical bonding

valence electrons

chemical equation fro photosynthesis

6H2O+ 6CO2 \>>>C6H12O6+ 6O2

is photosynthesis exothermic or endothermic

endothermic

difference between nonpolar and polar covalent bonds

nonpolar covalent is balanced and polar covalent is not. their difference in their electronegativity

metallic bond

sharing of delocalized electrons

three properties of metals

malleability, ductility, and conductivity

what is electronegativity

indicates relative ability of an atom to attract electrons in a chemical bond

what is the general structure of the atom

positive dense nucleus that contains neutrons and protons, empty space, orbitals that contain electrons

atomic number

number of protons identifies element

atomic mass

number of protons + neutrons

the average atomic is the

weighted average

metals and nonmetals form

ionic bonds

metals are likely to form (ion)

cation

nonmetals are likely to form (ion)

anion

difference between a nuclear and chemical change

chemical- happens with the valence electrons and form a new substance

nuclear- nucleus changes, element changes

what is half-life

the amount of time it takes for half of the radioactive isotope to decay

what part of the nuclear power plant controls the rate of fission and absorbs extra neutrons

control rod

what part of the nuclear power plant contains fissionable uranium material

reactor core

what part of the nuclear power plant turns mechanical force into electricity

generator

what part of the nuclear power plant spins when pushed by steam

turbine

democritus conclusion

matter is made of an indestructible particle called an atom

john dalton contributions

atomic theory

atomic theory

\-everything is made of an indestructible part called an atom

\-elements have the same atom

\-atoms don't get destroyed or created in a chemical reaction

\-combine together to make compounds

what was Thomson's model of the atom called

plum pudding

quantum mechanical model

atom is a wave, electrons are in orbitals, different sizes ans shapes for the orbitals

in the quantum mechanical theory, as the principle energy level get bigger...

\-oribtals gets larger

\-electrons spends more time away from the nucleus

\-electrons are less tightly bound to the nucleus

three types of nuclear reactions

radioactive decay; nuclear fission; nuclear fusion

radioactive decay

an unstable nucleus decays or emits a particle

nuclear fission

an unstable nucleus breaks up into smaller parts when hit with a nucleus

nuclear fusion

small nuclei combine to form a bigger nucleus

radiation

energy and particles that are emitted by radioactive atoms

types of radiation

* -x rays - energy
* gamma rays - energy
* alpha particles - particles, have mass
* beta particles - particles, have mass

nuclear energy

energy released from nuclear reactions

when do nuclear reactions occur

when the nuclei of atoms is changed through a reaction

where is nuclear energy stored

inside the atom, instead of in the bonds

isotopes

atoms of the same element with different number of neutrons

atoms

the basic unit of matter

why was Dimirti Mendeleev's periodic table unique

he was able to predict the properties of unkown elements

how is the modern periodic table organized by

atomic number, electron configuration, and recurring properties

electron configuration

arrangement of electrons in an atom

what does the electron dot diagram show

show the element with its valence electrons

octet rule

atoms tend to gain, lose, or share electrons in order to acquire a full set of valence electrons

chemical formula

tells us the number of atoms each element that are bonded to make a compound

ionic bond is made up of

cation and anion

how is an ionic compound held together

electrostatic force (opposites attract)

what does bonding do the the atom (energy)

lowers the potential energy of the atom

cations are ( + or -) ions

+ postitive

anions are ( + or -) ions

- negative

types of energy

>chemical potential energy

>light energy

>sound energy

>electrical energy

>mechanical energy

what is the sun powered by

fusion of hydrogen atoms

what is a mole

a mole is a unit used to measure the amount of atoms, molecules, ions etc.

avogadros number

6.022 x 10 ^23

king henry died by drinking chocolate milk

king - kilo

henry - hecto

died - deka

by - base

drinking - deci

chocolate - centi

milk - milli