Chem 1111

Examples of chemistry in every day life

cooking, manufacturing of products

Macroscopic “____ domain”

large

Examples of macroscopic domain

everything that can be sensed or seen

Microscopic “_____ domain”

small

Examples of microscopic domain

atoms and molecules, things that can only be visualized using a microscope

Examples of symbolic domain

chemical symbols, formulas, and equations

Components of the scientific method

Observations, Hypothesis, Experiment, Law, Theory

Types of observations

qualitative and quantitative

Qualitative

descriptions using observations

Quantitative

descriptions using numbers

Hypothesis

tentative explanation for a set of observations

A hypothesis puts observations into _____

a form that can be tested

Experiment

systemic observations or measurements mase under controlled conditions

Law

description of a phenomenon that allows for general predictions

Law of Definite Proportions

chemical substance always contains the same proportions of elements by mass

Who discovered the Law of Definite Proportions?

Joseph Proust

A law is ____

unlikely to change overtime unless a major error is discovered

Theory

Attempts to explain why nature behaves as it does

A theory is ____

incomplete and imperfect and evolved over time

Matter

anything that occupies space and has mass

Examples of matter

metal, tables, people, smoke

Mass

quantity of matter an object contains

Gas

substance that has neither a fixed shape or volume and expands to completely fill its container

Solid

relatively ridged substance that has a fixed shape and volume

Liquid

substance that has a fixed volume but not a fixed shape and will match the shape of its container

Physical Change

change of a matters state from one to another

Pure Substance

any matter that has a fixed chemical composition and characteristic properties

Homogeneous Mixture

mixtures where all portions are in the same state, have no boundaries, and are uniform

Examples of homogeneous mixtures

air, tap water

Heterogeneous mixture

mixtures where the composition is not completely uniform

Examples of heterogeneous mixtures

chocolate chip cookie dough, milk

Ways to separate a mixture into its components

distillation and crystallization

Distillation

makes use of different boiling points

Crystallization

makes use of differences in solubility

Element

substance that cannot be broken down into a simpler one by chemical changes

Compound

substance that contains 2 or more elements and has chemical and physical properties different than those of the elements it is composed of

Physical Property

a characteristic of matter that is nor associated with a change in the chemical composition

Example of physical property

density, color, hardness, boiling point and melting point

What physical property can only be observed with physical change

boiling/melting point

Chemical Property

the change or inability to change from one type of matter to another

Example of chemical property

flammability, reactivity, toxicity

How can chemical properties be identified?

with a chemical change

Extensive Properties

the mass and volume of a substance

Intensive Properties

when a property of a sample does ot depend on the amount of matter present

Example of intensive property

temperature

NFPA Diamond - what does the red represent?

Level of fire hazard

NFPA Diamond - what does the blue represent?

Level of health hazard

NFPA Diamond - what does the yellow represent?

Reactivity hazards

NFPA Diamond - what does the white represent?

Special hazards

What is the only type of measurement that is free from uncertainty?

counting, given that the objects being counted do not change while being counted

Conversion factor

ratio of two equivalent quantities with different measurement units

Who was the earliest person to formulate and idea of atoms and thought that all things were made of atoms

Democritus

Who used experiments and was able to isolate hydrogen gas formed from reacting metals with acids?

Robert Boyle

Who isolated different “airs” or gases, including oxygen?

Joseph Priestly

Who showed that hydrogen combined with oxygen form water?

Henry Cavendish

Who argued that oxygen and nitrogen are elements and clearly stated that elements were the basic unit of matter and could not be obtained from other materials?

Antone Lavoisier

Antone Lavoisier concluded that ___

a compound is a mixture of different elements bonded together, and revised the law of conservation of mass to the total mass of products after a reaction equals the total mass of the reactants

Who advanced the idea that all atoms of a particular element are identical?

John Dalton

5 postulates if Daltons atomic theory

Matter is composed of tiny, indestructible particles called atoms ; an element consists only of one type of atom, which has a mass that is characteristic of the element and is the same for all atoms of that element ; Atoms of one element differ in properties from atoms of all other elements ; a compound consists of atoms of two or more elements combined in a small, whole-number ratio ; atoms are neither created nor destroyed during a chemical change but instead are rearranged to yield substances that are different from those present before the change

Law of Conservation of Mass

states that if atoms are neither created nor destroyed during a chemical change, then the total mass of the matter present when matter changes from one type to another will remain constant

Law of Multiple Proportions

When two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element is a ratio of small, whole-numbers

Who proved that atoms were not the most basic form of matter?

J.J Thompson

Who used electrically charged oil droplets to calculate the charge of a single electron?

Robert Millikan

Who discovered that certain minerals emitted radiation?

Henry Becquerel was the first to discover that certain minerals, such as uranium, emitted radiation, which he termed radioactivity.

What are the 3 types of radiation?

Alpha, beta, and gammarays are the three types of radiation, differing in their composition and penetrating power.

Plum Pudding Model

is a historical atomic model proposed by J.J. Thomson, where electrons are embedded in a positively charged 'soup', resembling a plum pudding.

Rutherford Gold Foil Experiment

Experiment in which a stream of particles is aimed at a thin gold foil and examined how the particles scattered when they hit the foil to provide evidence of the nuclear model of the atom, leading to the discovery of the atomic nucleus.

Nuclear Model of the Atom

Demonstrated the existence of a positively charges nucleus which contained nearly all the atoms mass

Who discovered the neutron?

James Chadwick

Atomic number

number of protons in the nucleus of an atom

Mass number

Number of protons and neutrons in the nucleus of an atom

Chemical Symbol

Abbreviation used to indicate an element or atom of an element

Isotopes are ___

Identified with the atomic number but have different mass numbers due to varying numbers of neutrons.

Atomic Mass

the weighted average mass of an element's naturally occurring isotopes

How is atomic mass measured?

using a mass spectrometer

Avogadro’s Number

6.02 × 10²³

What does Avagadro’s number represent?

The number of atoms or molecules in one mole of a substance.

Mole

Amount of substance which contains as many elementary units as there are atoms in 0.012kg of Carbon 12 It is the SI unit for measuring the quantity of a substance.

Molar Mass

The mass of one mole of a substance, based on the sum of the atomic masses of its constituent elements.

Chemical Bonds

Attractive forces that hold atoms together in a molecule.

Ionic Bonding

A type of chemical bond that occurs when electrons are transferred from one atom to another, resulting in the formation of ions that attract each other due to opposite charges.

Covalent Bond

A type of chemical bond formed when two atoms share one or more pairs of electrons, resulting in the formation of a stable molecule.

Polar Covalent bond

A type of covalent bond in which the shared electrons are unequally distributed between the two atoms, resulting in a molecule with a slight electrical polesdue to the difference in electronegativity between the atoms.

Polymer

Formed when small molecules with identical structures combine into a large cluster

Molecular Formula

A representation of a molecule that shows the types and numbers of atoms present

Empirical Formula

A simplified representation of a chemical formula that shows the simplest whole-number ratio of the different types of atoms in a molecule.

Structural Formula

A graphical representation of a molecule that shows the arrangement of atoms and the bonds between them. Co

Condensed Structural Formula

A type of structural formula that shows the arrangement of atoms in a molecule using a linear format, combining groups of atoms together to simplify the representation.

Binary Compounds

Compounds composed of two different elements.

Binary Acids

Binary compounds that contain hydrogen and one other nonmetal element to frorn an acid

Polyatomic Ions

Ions composed of two or more atoms that are covalently bonded

Cation

A positively charged ionthat results from the loss of one or more electrons.

Anion

A negatively charged ion

Organic Compounds contain ____

a combination a combination of carbon and hydrogen, or hydrogen and nitrogen

Hydrocarbon

compounds that only consist of carbon and hydrogen atoms

Alkanes

hydrocarbons that are bonded together with only single bonds

Alkenes

hydrocarbons that contain one or more double bonds

Functional Groups

Atoms connected to carbon chains or rings of organic molecules

Ionic Compounds

when an element is composed of atoms that readily loose electrons reacts with an element that is composed of atoms that readily gain electrons

Covalent Compounds

Compounds that do not contain ions instead they consist solely of neutral molecules