chemistry exam ch 1-3

what are the properties of matter determined by?

chemical and physical properties of atoms and molecules

atom

submicroscopic particles matter which are building blocks for elements and molecules

molecule

2 or more atoms combine to make them. it can be made of the same element or different elements

chemistry

the science that seeks to understand the behavior of matter by studying the behavior of atoms and molecules (the study of matter)

strong bonds

make an object harder to break

what does it mean that science is empirical ?

it is based on obsesrvations and experiments

scientific law

A general hypothesis or statement about the relationship of natural quantities that has been tested over and over again and has not been contradicted

fact

A phenomenon about which competent observers can agree.

hypothesis

prediction

principle of falsifiability

for a hypothesis to be considered scientific, it must be testable and capable of being wrong

does data prove a hypothesis

no, it only supports a hypothesis

theory

unifying explaination of a scientific phenomena

matter

anything that has mass and takes up space, consisting of atoms and molecules in motion

the 3 states of matter

solid, liquid, gas

to measure the volume of a solid, use…

water displacement

structure of a solid

fixed volume and shape (tightly packed bonds

structure of a liquid

no shape but fixed volume (loose bonds)

structure of a gas

no shape or volume (very very weak bonds)

2 categories of matter

pure substances and mixtures

2 types of misxtures

heterogenous (layered boundaries like wet sand) and homogenous (no clear separation of the compounds)

element

substance that can not be broken down into a simpler substance

compound

substance of 2 or more elements in fixed definite proportions

homogenous mixture

composition is the same throughout (ex: air, bronze, sweet tea)

heterogeneous mixture

varries in composition throughout sample (ex: granite countertop)

methods of separating mixtures

decanting, distillation, and filtration

physical changes

a substance doesnt change into a new substance (phase change, ex: ice to water to steam)

physical properties (list)

density, color intensity, particle size, melting/freezing point, boinling point, texture

chemical change

a reaction forms a new substance

base unit of length

meter

base unit of mass

gram

base unit of time

second

amount of a substance

mole

base unit of electric current

ampere

base unit of luminous intensity

candela

precision

agreement and closeness of repeatable values. you can be precise but not accurate in measurements.

accuracy

agreement and consensus of measured values to the actual value

uncertainty/confidence factor

degree of measure value differs

atom

smallest identifiable unit of an element

Gerd Binning and Heinrich Roher

discovered “tunneling” current that allowed them to scan the surface on an atomic scale

what did Binnig and Roher’s discovery lead to?

electron scanning tunneling microscopy

law of conservation of mass

in a chemical reaction matter is neither created or destroyed

law of definite proportions

for a given compound the elements always combine in the same proportion

Law of multiple proportions

2 elements A and B can form different compounds by combining in different proportions and the ratio of these two is itself a small whole numebr

dalton’s atomic theory

-each element is composed of tiny indestructible particles called atoms

-all atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements

-atoms combine in simple whole number ratios to form compounds

-atoms of one element cannot change into atoms of another element. in chemical reaction atoms change the way that they are bound together with other atoms to form a new substance.

jj Thomson

did cathode ray experiment

RA millikan

did oil drop experiment showing that the particle had the same amount of charge as the hydrogen ion as thomson observed in his experiments

electron

negatively charged particle

neutrons

neutral particles

proton

positively charged particles

what is an atomic number?

number of protons

isotope

the same elements but with different mass due to varying number of neutrons.

ion

atoms or groups of atoms with a positive or negative charge

cation

when an atom loses an electron (positive charged ion)

anion

when an atom gains an electron (negative charged ion)

demitri Mendeleev

developed the modern periodic table

periodic law (2 points)

-when elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically.

-elements having similar physical and chemical properties fall within a column

how are the elements arranged (left to right)?

in increasing atomic number.

what are rows of the periodic table called?

periods

what are the columns of the periodic table called?

families

areas of the periodic table

main group metals

transition metals

inner transition metals-(lanthanides and actinides)

metalloids

nonmetals

properties of metals

solid at room temp (except mercury)

reflective

conduct heat/electric current

malleable and ductile

lose electrons and form cations

metaloids

can exhibit properties of both metals and nonmetals

known as semiconductors (poor conductors of heat)

solid at room temperature

nonmetals

can be found in all three states of matter

poor conductors of heat or electricity

solids are brittle

gain electrons to become anions

except for H mostly found in the upper right on the periodic table

elements within a family have…

-similar chemical and physical properties

-the same number of electrons

what do metals tend to form?

cations

what do nonmetals tend to form?

anions

what do metaloids form?

tend to form cations but can also form anions

mole

quantity used in chemistry

charge of Zinc

2+

silver charge

1+

what is the charge of aluminum?

3+

compound

made of atoms held together by chemical bonds

bond

attraction force between atoms

ionic bonds

formed between a metal and a nonmetal where an electron transfers from one atom to another. the resulting cation and anion are attracted to each other by electrostatic forces. they are the strongest type of bond. ionically bonded elements are known as ionic compounds

covalent bonds

occur between nonmetal elements. this bond arises from the mutual attraction of 2 nuclei for the same electron (sharing) refered to as molecular compounds. balance between attractive and repulsive forces

chemical formula

represents the composition of the substance

molecular formula

lists the exact number and types of atoms of which the molecule is composed.

empirical formula

relative type and number of atoms in the compound (simplest ratio)

Atomic elements

they exist by themselves, all metals are atomic

molecular element

doesn’t exist by itself

what net charges does a ionic compound have

zero

naming ionic compounds (including alkali and alkaline earth metals)

metal followed by the nonmetal

nonmetal ending exchanged with “-ide”

type 2 metal and nonmetal ionic

metal then nonmetal

metal’s oxidation state is indicated by roman numerals between the two

hydrates

ionic compounds containing a specific number of waters for each formmula unit

name molecular compounds

name first nonmetal

change ending of second nonmetal to “-ide”

use prefixes on both unless the first one is one (no subscript

acids

release Hydrogen (H+) when disolved in water

sour taste and low pH value (less than 7)

can dissolve many metals

binary acids

have only 2 elements, H+ and a nonmetal

how to name oxyacids

h cation and polyatomicc anion that contain atoms

take bace of nonmetal and add “-ic acid”

is there a difference between atomic weight and atomic mass?

no. it is the mass of one mole of the element

combustion analysis

burning of a known mass of compound and weighing the product. generally used for organic compounds containing C, H, and O and can determine the original amount of constituent elements.

organic compound

mainly made of C, H, sometimes O, N, P and S with traces of other elements (main focus is carbon) bond almost exclusively covalently. when carbon bonds they form straight/branched chains or rings

charge of Sc

3+

phosphate

PO4 charge=3-

Acetate

C2H3O2 charge -1

hydroxide

OH charge -1

carbonate

CO3 charge -2

ammonium

NH4 charge 1+

sulfate

SO4 charge 2-

chromium type 2 metal

Cr 2+ or 3+

Iron type 2 metal

Fe 2+ or 3+