Chemistry
is the study of matter and the changes it undergoes.
Scientific Method
is a systematic approach to research.
Nx10^n
Scientific Notation
Significant Figures
are the meaningful digits measured or calculated quantity.
Accuracy
tells how close a measurement is to the true value of the quantity that was measured.
Precision
refers how closely two or more measurements of the same quantity agree with one another.
Matter
is anything that occupies space and has mass.
Substance
A classification of matter wherein there are definite constant properties
Mixture
A classification of matter wherein there are two or more substances
Element
A type of pure substances wherein it cannot be separated by any means
Compound
A type of pure substances wherein two or more substances can be separated.
Homogenous
a type of mixture that has the same proportions of its components in a given amount of sample.
Heterogenous
a mixture in which the composition is not uniform throughout the mixture.
Solid
is a state of matter wherein it has a definite shape and volume because the molecules that make it up the are packed closely together and move slowly
Liquid
is a state of matter wherein it has a definite volume but takes the shape of its container.
Gas
is a state of matter wherein it has neither a definite volume nor a definite shape.
Plasma
a state of matter which is made by heating gas until its electrons have sufficient energy to escape the hold of the positively charged nuclei.
Bose-Einstein Condensate
is a state of matter which has the lowest absolute zero.
Physical Property
is a characteristic of matter that can be observed and measured without changing the chemical identity of the sample.
Chemical Property
is a characteristic of a particular substance that can be observed in a chemical reaction.
Intensive Property
is a property of matter that depends only on the type of matter in a sample and not on the amount.
Extensive Property
is a property that depends on the amount or density of matter in a sample.
Sublimation
The process in which a solid changes directly into vapor without first forming a liquid.
Liquid and Gas
two states of matter which occupies the whole space of available.
Liquid and Gas
which two types of matter fall under the term fluids?
Atom
is the basic building block of matter. It is the smallest particle of element.
Atomos
The term used by Democritus which means uncuttable or inidivisible.
Law of Conservation of Mass
A law which states that matter can be neither created nor destroyed.
Joseph Proust’s Law of Definite Proportions
A law that states: different samples of the same compound always contain its constituent elements in the same proportion by mass.
Joseph Proust
is a French chemist who one who discovered the Law of Definite Proportions
Law of Multiple Proportions
A law which states that two elements can combine to form more than one compound, the two masses of one element that combine with a fixed mass of the other element are in ratios of small whole numbers.
Atomic Number
is the number of protons (or number of electrons) in the nucleus of each atom of an element.
Z
Is the letter or symbol that denotes the Atomic Number of an element.
Mass Number
is the total number or neutrons and protons present in the nucleus of an atom of an element.
A
is the letter or symbol that denotes the mass number of an element.
Mass Number
Number of Protons + Number of Neutrons = _____
Mass Number
Atomic Number + Number of Neutrons = _____
Isotopes
are atoms that have the same atomic number but different mass numbers.
Average mass of an element
the sum of the masses of its isotopes, each multiplied by its natural abundance.
Mole
is the amount of pure substance containing the same number of chemical units, as there are atoms in exactly 12-grams of carbon-12.
Avogadro’s Number
it is the number of units in one mole of any substance which is constantly equal to:
NA = 6.02x10^23 particles/mole
Periodic Table
is a chart in which elements having similar chemical and physical properties are grouped together.
Periods
are the horizontal rows of the periodic table.
Group or Families
are the vertical rows of the periodic table.
Niels Bohr
The concept that electrons revolve around the nucleus in specific paths called orbits or energy levels was proposed by
24.31 amu
Naturally occurring magnesium consists of 78.7% of 24Mg, with atoms of mass 23.98504 amu, 10.13% of 25Mg, with atoms of mass 24.98584, and 11.17% 26Mg, with atoms of mass 25.98259 amu. Calculate the atomic mass of magnesium.
50.4% & 49.6%
Calculate the percentage of bromine atoms that have a mass of 78.9183 amu and the percentage that have a mass of 80.9163 amu. The atomic mass of bromine is 79.909 amu, and these are the only two naturally occurring isotopes.
Metal
is an element that is a good conductor of heat and electricity
Nonmetal
is an element that is a poor conductor of heat and electricity
Metalloids
is an element that is an intermediate of metals and nonmetals
Cation
a positively charged ion, i.e. one that would be attracted to the cathode in electrolysis.
Anion
a negatively charged ion, i.e. one that would be attracted to the anode in electrolysis.
Ion
is an atom or group of atoms that has a net positive or negative charge.
Chemical Formula
are formula used to express the composition of the molecules and ionic compounds in terms of chemical symbols.
Molecular Formula
shows the exact number or atoms of each element in the smallest unit of a substance.
Molar Mass
is defined as the mass (in grams or kilograms) of 1 mole of units (such as atoms or molecules) of a substance.
g/mol or kg/mol
the units of molar mass are
Molecular Mass
it is sometimes called Molecular Weight and is the sum of the atomic masses (in amu) in the molecule.
Percent Composition
is obtained by dividing the mass of each element in 1 mole of the compound by the molar mass of the compound and multiplying by 100 percent.
Chemical reaction
is a process in which a substance (or substances) is changes into one or more new substances.
Reacts with
In writing chemical equations, “plus” sign (+) means
To yield
In writing chemical equations, “arrow” sign means
Solution
is a homogenous mixture of two or more substances
Solute
is the substance present in a smaller amount.
Solvent
is the substance present in a larger amount.
Aqueous Solution
is a solution in which the solute initially is a liquid or a solid and the solvent is water.
Electrolyte
is a substance that, when dissolved in water, results in a solution that can contain electricity.
Nonelectrolyte
does not conduct electricity when dissolved.
85g
What is the mass of 5.00 mol of NH3?
2.01x10^24
Calculate the number of particles on 56.7g of NH3?
35%
Determine the percent composition of nitrogen in NH4NO3?
Concentration of a Solution
is the amount of solute present in a given quantity if solvent or solution.
Molar
or molar concentration, is the number of moles of solute per liter of solution.
Dilution
is the procedure for preparing a less concentrated solution from a more concentrated one.
Synthesis reaction
a type of chemical reaction that occurs when two or more reactants combine to form a single product.
Decomposition reaction
is a reaction in which a compound breaks down into two or more simpler substances.
Single Replacement
sometimes called a single displacement reaction, is a reaction in which one element is substituted for another element in a compound.
Double Replacement
are reactions in which the positive and negative ions of two ionic compounds exchange places to form two new compounds.
Molality
or molal concentration, is the amount of substance dissolved in a certain mass of solvent.
Molarity
is the amount of substance in a certain volume of solution. It is defines as the moles of a solute per liters of a solution.
Molarity
It is also known as the molar concentration of a solution.
Acids
have sour taste, cause color changes in plant dyes, react with certain metals, and react with carbonates and bicarbonates.
Acid
a chemical substance that neutralizes alkalis, dissolves some metals, and turns litmus red; typically, a corrosive or sour-tasting liquid of this kind.
Bases
have bitter taste, feel slippery, and cause color changes in plant dyes.
Base
a substance that can accept hydrogen ions in water and can neutralize an acid.
Neutralization
is a reaction between an acid and a base.
Aqueous
acid-base reactions that produce water and a salt.
Catalyst
A substance added to the solution to speed up chemical reactions
2.0`
Calculate the molality of a solution containing 0.5 mol of solute in 250g of solvent.
0.833
Calculate the molarity of 1.5 L of a 2.5 M solution after it has been diluted to a 4.50 L
Carbonic Acid
The carbon dioxide is soluble in water. The acid formed when it dissolves is called
Combination reaction
the reaction CaO + H2O to Ca(OH)2 is an example of
7
A neutral solution has a pH of
1.0
Calculate the pH of 0.100 M HCl
Antoine Lavoisier
Debunked the phlogiston theory. Uncovered the truth in combustion. Names hydrogen and oxygen. Identified sulfur and predicted silicon. Published the first Chemistry book.
Ampotheric
A substance that can act as both acid and base is called
More than 7
The pH of an aqueous solution of a sodium acetate is
Basicity
The number of hydrogen ions obtainable from a molecule of an acid is called
Antoine Lavoisier
The Father of Modern Chemistry
Dmitiri Mendeleev
A Russian Chemist who created the framework that became the modern periodic table, leaving gaps for elements that were yet to be discovered.