Honors Chemistry Semester 1 Review

Mass

amount of matter

Volume

amount of space an object occupies

Plasma

4th state of matter, ionized gas

Atom

smallest unit of matter

Element

a pure substance made of one type of atom that cannot be broken down to simpler, stable substances

Compound

a substance made up of two or more elements chemically bonded together

Molecule

a group of atoms bonded together, representing the smallest unit that can take part in a chemical reaction

Diatomic element

two atoms of the same element bonded together

Mixture

a blend of two or more kinds of matter, each of which retains its own identity and properties

Homogenous mixture

a mixture in which the composition is the same throughout (ex. Solution)

Heterogeneous mixture

a mixture in which the composition is not the same throughout

Extensive property

does depend on the amount of matter

Extensive property examples

mass, volume, amount of energy

Intensive property

does not depend on the amount of matter

Intensive property examples

density, b.p., m.p., conductivity

Metals

solids at room temp, luster, malleable, ductile, conductors

Nonmetals

liquids and gases at room temp, brittle, poor conductors

Metalloids

solids at room temp, luster, semi-conductors

Distillation

separating liquids based on boiling point

Decanting

separating a solid and a liquid by pouring off the liquid after the solid settles

Filtering

separating a solid and a liquid by pouring the mixture into a filter - the liquid will pass through but the solid will remain

Evaporation

a method to separate water from a dissolved liquid

Chromatography

passing a mixture a medium where the compounds move at different rates

Accuracy

closeness of a measurement to the accepted value

Precision

closeness of a group of measurements

Percent error

used to determine accuracy

Percent error formula

[(experimental - accepted) / accepted] x 100

Significant figures

all the digits known with certainty plus an estimated digit

Sig Fig Rules

All nonzero integers are significant; Captive zeroes are always significant; Leading zeroes are never significant; Trailing zeroes are significant if there is a decimal point.

add/sub whole number sig fig rule

the final sig fig is in the same place value as the left most uncertain digit

add/sub decimal sig fig rule

as many decimal places as the least precise piece of data

multiply/divide sig fig rule

as many total sig figs as the least precise piece of data

Scientific method

a logical approach to solving a problem

Quantitative data

numerical data

Qualitative data

observations made using senses

Control

the standard used for comparison in an experiment

Theory

hypothesis that has withstood many tests

Density

ratio of mass to volume (m/V)

Law of Conservation of Mass

mass is neither created nor destroyed during ordinary chemical reactions or physical changes

Law of Definite Proportions

A single chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound

Law of Multiple Proportions

if two or more compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers

Dalton's Atomic Theory

All matter is composed of small particles called atoms; Atoms of an element are identical in size, mass, and other properties; Atoms cannot be subdivided, created, or destroyed; Atoms of different elements combine in simple whole number ratios to form compounds.

Thompson's Atomic Theory

concluded that negatively charged particles called electrons existed - atoms are electrically neutral, so atoms must contain a positive charge to balance the negative electrons

Cathode ray tube experiment

rays were deflected away from negatively charged objects

Millikan's conclusions

used the charge to mass ratio to determine the mass of an electron (so small it's considered negligible), concluded that other particles must be present to account for the mass

Oil drop experiment

measured the charge of an electron

Rutherford's conclusions

the alpha particles hit something small and dense, called a nucleus

Gold Foil experiment

1 in 8000 alpha particles were deflected back

Isotopes of hydrogen

protium (no neutron), deuterium (1 neutron), tritium (2 neutrons)

Alpha emission

least penetrating, blocked by a sheet of paper

Alpha particle

⁴₂He

Beta emission

more penetrative, blocked by aluminum foil

Beta symbol

⁰_-1e- OR ⁰_-1β

Positron emission

more penetrative, stopped by aluminum foil

Positron symbol

0+1e- OR 0+1β

Gamma emission

electromagnetic radiation, stopped by lead

Gamma symbol

⁰₀Ƴ

Symbol for an isotope

hyphen notation (ex. Hydrogen-1)

Extensive property

Does depend on the amount of matter.

Extensive property examples

Mass, volume, amount of energy.

Intensive property

Does not depend on the amount of matter.

Intensive property examples

Density, boiling point (b.p.), melting point (m.p.), conductivity.

Metals

Solids at room temperature, luster, malleable, ductile, conductors.

Nonmetals

Liquids and gases at room temperature, brittle, poor conductors.

Metalloids

Solids at room temperature, luster, semi-conductors.

Distillation

Separating liquids based on boiling point.

Decanting

Separating a solid and a liquid by pouring off the liquid after the solid settles.

Filtering

Separating a solid and a liquid by pouring the mixture into a filter - the liquid will pass through but the solid will remain.

Evaporation

A method to separate water from a dissolved liquid.

Chromatography

Passing a mixture through a medium where the compounds move at different rates.

Accuracy

Closeness of a measurement to the accepted value.

Precision

Closeness of a group of measurements.

Percent error

Used to determine accuracy.

Percent error formula

[(experimental - accepted) / accepted] x 100.

Significant figures

All the digits known with certainty plus an estimated digit.

Sig Fig Rules

Rules that determine which digits are significant in a number.

Scientific method

A logical approach to solving a problem.

Quantitative data

Numerical data.

Qualitative data

Observations made using senses.

Control

The standard used for comparison in an experiment.

Theory

Hypothesis that has withstood many tests.

Density

Ratio of mass to volume (m/V).

Law of Conservation of Mass

Mass is neither created nor destroyed during ordinary chemical reactions or physical changes.

Law of Definite Proportions

A single chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound.

Law of Multiple Proportions

If two or more compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers.

Dalton's Atomic Theory

All matter is composed of small particles called atoms.

Thompson's Atomic Theory

Concluded that negatively charged particles called electrons existed.

Cathode ray tube experiment

Rays were deflected away from negatively charged objects.

Millikan's conclusions

Used the charge to mass ratio to determine the mass of an electron.

Oil drop experiment

Measured the charge of an electron.

Rutherford's conclusions

The alpha particles hit something small and dense, called a nucleus.

Gold Foil experiment

1 in 8000 alpha particles were deflected back.

Isotopes of hydrogen

Protium (no neutron), deuterium (1 neutron), tritium (2 neutrons).

Alpha emission

Least penetrating, blocked by a sheet of paper.

Beta emission

More penetrative, blocked by aluminum foil.

Positron emission

More penetrative, stopped by aluminum foil.

Gamma emission

Electromagnetic radiation, stopped by lead.

Symbol for an isotope

Hyphen notation (ex. Lithium - 7).

Heterogeneous mixture

a mixture in which the composition is not the same throughout (ex. Milk, blood, trail mix)

Dalton's Atomic Theory

All matter is composed of small particles called atoms; Atoms of an element are identical in size, mass, and other properties; Atoms cannot be subdivided, created, or destroyed; Atoms of different elements combine in simple whole number ratios to form compounds