Chemistry Chapter 1 PDF

Chemistry Chapter 1 Three states of matter: solid, liquid, and gas ​ Solid ○​ Has a definite volume ○​ Maintains its shape regardless of its container ○​ Has particles that lie close together in a regular three-dimensional array ​ Liquid ○​ Has a definite vo...

Chemistry Chapter 1 Three states of matter: solid, liquid, and gas ​ Solid ○​ Has a definite volume ○​ Maintains its shape regardless of its container ○​ Has particles that lie close together in a regular three-dimensional array ​ Liquid ○​ Has a definite volume ○​ Takes the shape of its container ○​ Has particles that are close together that can randomly move around, sliding past one another ​ Gas ○​ Has no definite shape or volume ○​ Expands to fill the volume and assumes the shape of its container ○​ Has particles that are very far apart and move around randomly Physical/chemical properties and changes ​ Physical properties: can be observed or measured without changing the composition of the material ○​ Examples: boiling point, melting point, solubility, color, odor ​ Physical change: alters the material without changing its composition ○​ Examples: melting ice to form liquid water, boiling liquid water to form steam ​ Chemical properties: determine how a substance can be converted into another ○​ Does it dissolve or react with a certain chemical ​ Chemical change/chemical reaction: converts one substance into another; usually not reversible ○​ Examples: a piece of paper burning, metabolizing an apple for energy, or oxygen and hydrogen combining to form water Pure substances and mixtures ​ Pure substance ○​ Composed of a single component ○​ Has a constant composition, regardless of sample size and origin of sample ​ Ex: water is always H2O ○​ Cannot be broken down to other pure substances by a physical change ○​ Table sugar (C12H22O11) and water (H2O) are both pure substances ​ Mixture ○​ Composed of more than one substance ○​ Can have varying composition (any combination of solid, liquid, and gas) depending on the sample  ○​ Can be separated into its components by a physical change ​ Ex: can pull ice out of water, can pull marshmallows out of lucky charms ○​ Sugar dissolves in water=mixture Elements and compounds ​ Element: a pure substance that cannot be broken down by a chemical change ​ Compound: a pure substance formed by chemically joining two or more elements Matter ​ Matter: anything that has mass and takes up volume ○​ Stuff is volume Chemistry ​ Chemistry: the study of matter- its composition, properties, and transformations Significant Figures ​ Definition: all the digits in a measured number including one estimated digit ​ All nonzero digits are always significant ○​ 65.2= 3 Sig Figs ○​ 255.345= 6 Sig Figs ​ Rule 1: A zero COUNTS as a sig fig when it occurs: ○​ Between two nonzero digits, as in ​ 29.05= 4 sig figs, 1.0087= 5 sig figs ○​ At the end of a number with a decimal place ​ 3.7500= 5 sig figs, 620= 3 sig figs ​ Rule 2: A zero DOESN’T COUNT as a sig fig when it occurs: ○​ At the beginning of a number ​ 0.00245= 3 sig figs, 0.008= 1 sig fig ○​ At the end of a number that does not have a decimal ​ 2570= 3 sig figs, 1245500= 5 sig figs Scientific Notation ​ y x 10^x ○​ Y: coefficient: number between 1-10 ○​ X: exponent: any pos or neg whole number ​ Ex: 500= 5x10^2 ​ Ex: 0.00453= 4.53x10^-3 ​ Scientific notation on calculator: Use EE in place of x10, and follow with exponent value Sig Figs Rules for multiplication and division ​ The answer has the same number of sig figs as the original number with the fewest significant figures ​ Ex: 351.2 x 5.5 = 193.16 ○​ Round to two sig figs, answer is 190 Sig Figs rules for addition and subtraction ​ The answer has the same number of sig figs as the original number with the fewest decimal places ​ Ex: 10.11- 3.6= 6.5 ​ 3.6 has the 2 amount of decimal places, so answer should have 2 decimal places Density ​ A physical property that relates the mass of a substance to its volume ​ Density = mass (g)/ volume (mL or cc) ​ To convert volume (mL) to mass (g) ○​ mL x g/mL =g ​ To convert mass (g) to volume (mL) ○​ g x mL/g = mL ​ Ice floats in water because the density of water is less than water ​ Water density = 1.00 g/mL Volume displacement ​ Final volume - initial volume = volume of object Specific gravity ​ Ratio between density of substance and density of water ​ Density of substance g/mL/ density of water 1.00 g/mL ​ Normal urine has a specific gravity of 1.003-1.030 Conversion factor ​ Definition: term that converts a quantity in one unit to another unit ​ Original quantity x conversion factor = desired quantity ​ Written as equalities with units that cancel each other out Percents ​ Percent factor gives the ratio of the parts to the whole (parts per 100 parts) ​ % = parts/whole x100 ○​ Uses same unit in num and denom Temperature conversions ​ Three temperature scales used: degrees Fahrenheit, degrees Celsius, and Kelvin ​ To convert from C to F: F= 1.8(C)+32 ​ To convert from F to C: C= F-32/1.8 ​ To convert from C to K: K= C+273 ​ To convert from K to C: C= K-273  Chapter 2 Nucleus ​ Central region of the atom where protons and neutrons are concentrated Electrons ​ Outside the nucleus and orbit about it because they are attracted to the positive charge in the nucleus ​ Extremely tiny ​ Negative electrical charge ​ Symbol: e- ​ Relative mass: 0.00055 ​ Relative charge: -1 Protons ​ Has the same amount of charge as an electron, but its charge is positive not negative ​ Symbol: p+ ​ Relative mass: 1 ​ Relative charge: +1 ​ Located in the nucleus of an atom Neutrons ​ Particle with about the same mass as a proton but with no electrical charge ​ Symbol: n^0 ​ Relative mass: 1 ​ Relative charge: 0 (neutral) ​ Located in the nucleus of an atom Mass number ​ The sum of the number of protons and neutrons Atomic number ​ Defines the identity of an element ​ Elements are listed in order of atomic number ​ The number above the atomic symbol ​ The number of protons in the atom is called the atomic number ​ The atomic number of an element also gives the number of electrons of that neutral element ​ 1 amu = 1.6606 x 10^-24g Atomic mass ​ A weighted average mass (commonly referred to as the atomic weight) of an element ​ An atomic mass unit is 1/12th the mass of a 12C atoms ​ Based largely on the number of protons and neutrons in their nucleus Metals ​ Solids at room temperature (except mercury) ​ Shiny ​ Good conductors of heat and electricity ​ Malleable (can be shaped) ​ Ductile (can be drawn into wires) ​ High melting point and density ​ Readily combine with nonmetals to form compounds but rarely combine with other metals Nonmetals ​ Not shiny ​ Daily low melting points and densities ​ Poor conductors of heat and electricity ​ Solid nonmetals are very brittle ​ Combine with nonmetals to form molecular compounds and with metals to form ionic compounds Metalloids ​ Metalloids have properties between metals and nonmetals ​ Positioned diagonally on the periodic table, separating the metals and nonmetals Alkali metals ​ The first column of elements Alkaline earth metals ​ The second column of elements Halogens ​ The next to last column of elements Noble gases ​ The last column of elements Isotope ​ Atoms of an element with the same atomic number but different numbers of neutrons ​ Isotop symbol: mass number in top left subscript, atomic number (protons) in bottom left subscript, element symbol after Electron arrangement (electron configuration) ​ Electrons are organized according to their energies into sets called shells ​ Shells are divided into subshells, labeled s, p, d, and f ○​ S can hold up to 2 electrons, p:6, d:10, f:14 ​ Electron configurations: shorthand descriptions of the arrangements of electrons in atoms Valence electrons ​ Electrons in the highest-numbered shell  ​ Equal to the group number (vertical column) ​ For groups 1-2, the number of valence electrons is equal to the group number ​ For transition metals (groups 3-12), use the modified d electron count method ​ For groups 13-18, the number of valence electrons is the group number minus 10 Number of electron levels Atomic size Ionization energy ​ Measure of strength by which an electron is held in place ​ The amount of energy required to remove an electron from an isolated atom or molecule Electron dot symbols Diatomic elements ​ Important elements that exist as two atom combinations ​ Have no fear of ice cold beer: ○​ Hydrogen (H2), Nitrogen (N2), Fluorine (F2), Oxygen (O2), Iodine (I2), Chlorine (Cl2), Bromine (Br2) Atomic Radius ​ Largest radius = close to Francium ​ Smallest radius = close to Fluorine ​ Increases as you move down a group ​ Decreases as you move across a period